iMessage Sync Issues Post Sonoma 14.0 Update

*A Solution At Last!*

After a few weeks of nothing changing, even with the latest update to Sonoma, I was at my wits end. Even worse was that the synching issue had now hit my iCloud Drive and I was unable to access any of my files or anything within numbers and pages. Preview wouldn't work and then one by one my other programs such as Mail started to falter too. My iMac had become unusable. So I called Apple Support and spent from Friday to Sunday trying to get a solution. I even erased my HD and re installed Sonoma and a back up from my Time Machine and this still didn't solve the problem. However..........

I was finally put through to a senior Apple advisor. We created a new User Account on the iMac and transferred over all my important files and then added my Apple ID iCloud account and everything started to reappear and work correctly. iMessages appeared in Sync with my iOS devices and I could access iCloud Drive! There appeared to have been some kind of corruption within my original user account and it was only getting worse. Creating a new user account has completely changed everything back to a new working efficient iMac, in Sync with my iPad and iPhone. Just also to confirm that all those entries that have said just open up iCloud settings and hit the sync button etc etc that didn't work or show up for me, now do so and I can hit the SYNC button and it Sync almost straight away. SO..........

I would suggest you create a new USER profile and open yourself up in that and add your Apple ID / iCloud account to it, as you would your original user profile and test it and see that everything loads up and starts synching. If it does then copy across your important files and folders in Finder from your old user profile to the new one. Once you have completed all this just check again all is working fine. I was then advised to not delete the old user profile for a couple of weeks until I was happy I had everything I needed from the old profile before deleting it and getting rid of what ever was causing the corruption. We still didn't get to the bottom of what has caused all this in the first case but I now have a working, efficient and fast iMac, back fit for purpose. I hope this helps all those who like me, were starting to doubt my own sanity! Good luck !!

(PS you can't add a new user profile account with the same name as your original one, so you have to make sure it is different even if it is one letter or number different).

I was having this same exact issue and on my mac I went to Messages -> settings and I clicked "sync across iCloud". I let that simmer for a bit and do it's thing, turned my phone off in the meantime. Turned my phone back on and all of a sudden all the new messages started showing up in both places. To see if it was a sync issue with cloud (and because it kept annoying me that it would show "syncing with iCloud" at the bottom of the messages box on my mac), I went back to the settings and unclicked sync and it still works.

Maybe try that? Good luck!

I solved my trouble with this but not sure if its related to the same trouble others are having...

I wrote yesterday about how I was having this sync issue but decided to format and install Sonoma 14.3.1 from scratch. I still was struggling to get things to sync from the Messages app on macOS in settings where you turn on iCloud sync and there is a button there to sync. Then later in macOS settings under iCloud and then "Messages in iCloud" I noticed this window I didn't see before. It showed a little window showing how many messages were in iCloud and a way to enable sync there and a sync button. So I clicked that then messages began to show up in my Messages app.

Ever since they began trying to make macOS look like iOS it's been such a mess with settings like this. Multiple settings or settings found in multiple places. You can't just go to one setting and have things change, you have to go all over or even on a different device or sign into iCloud on the web to finally have a setting change. Glad my trouble is fixed now but I wish things were not so confusing. I always knew to go to the app to turn on sync but now it's in both the app settings and macOS settings.

I purchased a new Macbook Pro 14" M3 and since I set it up over a month ago it has never synced all my iMessages. When I open it up after sleep it shows many messages marked unread that have been read on other devices. New messages are not synced. Sometimes a few messages will sync.

I have done all the troubleshooting such as disabling imessage and enabling. Logging in/out of iCloud. I have rebooted and checked all iMessage settings in my iphone as well and rebooted it same as laptop. Tried opening up imessage settings and click sync now but that does nothing to fix this. Been in touch with apple support and they have been unable to provide a fix or acknowledge this is not an isolated incident

I currently have iPhone, Mac Studio and 4 ipads that all sync iMessage correctly. It is ONLY the new Macbook Pro that never has consistently synced since I set it up. It's running latest Sonoma version. I set the battery settings so it has network access even when sleeping in hopes that it would sync. I have tried leaving on battery for 12 hours and used Caffeine to keep laptop awake for several hours hoping it would sync eventually.

I was sitting at my Mac Studio and somebody sent me a message via iMessage (not sms) and it came in on my ipad and Mac Studio and nothing on my laptop even while it was open and plugged in next to me. I shut the Macbook down and rebooted it and some messages synced but still missing many.

The ONLY solution I have found that 100% fixes this on my new Macbook is to keep the laptop connected to power 24/7. If I do that imessage works perfectly. I can also keep the Macbook off power BUT keep the lid open and it seems to sync fine. If I close the laptop lid and it is off power syncing simply doesn't work and doesn't catch up ever until I connect to power, go to system settings and force sync (sync in imessage settings does nothing).

So at least on the laptop it appears this has something to do with power management and network access but the excuse the laptop is simply saving power when the lid is closed is BS. Our ipads/iphones all sync in realtime perfectly while on battery and screen off so there is no way the laptop needs to "shut down" in sleep mode and not take in imessages just like ipad/iphone does especially considering I have network access enabled during sleep. This seems like a Sonoma bug. If it doesn't get fixed in the next few months I will likely sell the Macbook and just take the loss. I can't have messages from personal and business - many times urgent - just not arrive or sync. iMessage is apple's lock in and if it doesn't work I don't need the apple hardware. The laptop was for backup in case the Mac Studio ever failed and for when I travel. I'll just take the ipad on trips like I used to and deal with it if there is no fix coming.

Troubleshooting iMessage Sync issues with my Mac and iPad (solved)

I recently noticed that my Mac was not syncing iMessage messages with my iPhone. I went through many Apple support articles and tried every combination of making sure that iCloud messages was turned on for all of my devices, turned off/on iMessage syncing to the cloud, and signed out and into my account from all of my devices. Nothing worked. No syncing. I then noticed that my iPad was also not syncing messages as well. After more searching for a resolution, I found an article that said to make sure my phone number was added to my account at https://appleid.apple.com. When I logged into my account, my phone number was listed under “Email & Phone Numbers” but it had a strange error message that my phone number did not have a SIM card associated with it and therefore couldn’t be used for iMessage and FaceTime. I then looked at my phone under Settings->Messages under “Send & Receive.” I found that only my Apple ID was listed, not my phone number. I then added my phone number to the list of items where “YOU CAN RECEIVE IMESSAGES TO AND REPLY FROM”  and made sure it was checked. Once this was done, I signed out of iMessage on my mac and signed back in. At that point iMessage syncing seemed to be working again. I also received an alert on my Mac and iPad that I could now enable phone calls over wifi. This happened after adding my phone number back to my iCloud “Email & Phone Numbers.” 

Thinking back on when this problem first started, it appears to be coincidental with recently upgrading to Sonoma and/or switching from AT&T to T-Mobile. Again, I’m not sure if this correlation is significant, but I thought I would put this information out there in hopes that it will help someone solve their iMessage syncing issue. I also had to disable and enable iMessage iCloud sync on my iPad before it started working correctly. 

As I stated above, I had problems when I updated to 14.1.2. I actually ended up having problems with many apps besides messages: Apple mail, contacts...

I thought if I could update to 14.2, that might help but I was unable to. I would receive an error message that the install couldn't be completed. After trying numerous things, I was finally able to start up in Safe Mode (Start up your Mac in safe mode - Apple Support) and then I installed the latest update. That worked and I have had no problems since running 14.2 (except the wallpaper keeps going back to Sonoma no matter what I do, but that is acceptable).

This must be a (synchronization) bug:

• Open (macOS, Sonoma) Settings, choose "Internet Accounts"
• Choose "iCloud" and click on "Show More Apps..." button
• Select "Messages in iCloud"
• The fourth control, "Status" shows "Not synced" and offers a "Sync Now" button
• Clicking on the "Sync Now" flashes "Syncing with iCloud"... then returns to "Not synced"
• ...even though all other internet functions work as expected — including sending messages from the macOS/Messages.app.

From the brief time my MBP tries to synchronize with iCloud, it should follow that either iCloud outright refuses syncing for macOS/Sonoma only and so is a server-side bug, or macOS (Sonoma, 14.4.1 in my case) has too short of an internal "timeout" setting.

As observed by others, Messages does synchronize eventually, and even interleaves the messages in a thread correctly, should I use macOS>Messages to send new messages.

➤ In fact, sometimes, the very action of sending a message via macOS/Messages.app triggers a (complete, properly interleaved) synchronization.

I bought a new MacBook Air recently and rebuilt (not using Time Machine) my computer and everything was working as it should with little to no delay in my messages. Late in the day yesterday, I turned on a few desktop widgets (right click don't he desktop and "edit widgets") for the first time on this computer. These widgets connect to my iPhone to pull content (from random apps). My messages stopped working this morning. I then turned off the widgets, restarted and it didn't resolve this issue. I checked the activity monitor and searched for widgets, and the ones that appeared to be off were still running in the background. I force quit the widgets from activity monitor, restarted and my messages are functioning again. Hope this helps.

I experienced the exact same issue after I upgraded to Sonoma 14.0. (I also lost the ability to sync my calendars between iCal, MS Teams, and Outlook.

After many trial and errors, I believe I have figured it out.

First, the update switched my computer iMsg to my email address rather than my phone number. I had to switch it back. That merged my iMsgs to the same threads, but not my text messages from Android users. I had to turn off, and then turn on again the share text messages on my phone. That appears to have resolved the issue, although it didn't catch me up. Only new texts show.

For my iCal, I had to uninstall my MS Exchange account and reinstall it in order to get it to actually sync to my iCal. That took almost 3 hours of attempts to finally get it right.

Good luck.

What I was having to do was actually go into Settings. Log out of iCloud and log back in. That had other ramifications that I had to ten deal with but it fixed it. So far in 14.1 it has not broken since then.

The fix for me was logging out of iMessage from the Messages app (Messages / Settings...) and logging back in on my MacBook Pro. My phone number wasn't showing before under iMessage. After the log out/log on it is. And everything is working.

I don't know if this is the OP's issue but I did track down what was causing it for me. In my case I had purchased a new Macbook and messages wasn't syncing properly, especially when I was attempting to log into web pages that required a code sent my phone via SMS. I found the setting in my phone of all places, and not on my Macbook. In my iPhone I went to "Settings > Messages > Text Message Forwarding", and discovered that my shiny new Macbook was there but had not been enabled. I enabled it and restarted the phone for good measure, and that solved the issue for me.

My devices: iPhone 13 Pro Max iOS 17 and 3d Gen iPad Pro..11 inch.. both with the 17.4.1

iOS and a M1 Mac-mini with Sonoma 14.4.1. For quite a while I had similar sync issues and also

sync issues with deleting iMessages. Followed the above suggestions and this solved the issue. Actually

I turned the 'sync' between the iPhone and other devices "OFF' and then back 'ON' after a couple of

minutes. Now all syncing between the three devices, including the delete function. This 'fix' worked for

my devices. Current rewards do not guarantee future success!! Also very disappointed that APPLE has not

reached out with a fix for this issue. This time self help with community effort seems to be a partial fix but a real

fix should be forthcoming from the APPLE 'experts'!

Partial & Temporary solution: When I’m not able to log into my AppleID for iMessages on my MacMini on Sonoma 14.1.1 I restart then log on successfully where iMessage syncs with my iPhone & iPad.

its not fully fixed yet. till try this one manually at regular intervals.

open messages on mac>> go to settings >> switch to @messages tab and click on sync now.

Do this atleast once for few days. that might help.