External SSD keeps disconnecting after upgrading to Sonoma

This is 100% a Sonoma issue. Same happened to my Samsung 1GB drive that is connected to the Mac mini M2 Pro after upgrading to Sonoma. Also did the dance (First Aid, then reformat) same issue. Hope 14.01 will do the trick.

I had the same exact thing with the ScanDisk portable extreme 1TB, but the problem is with the drive itself, the controller is a bad quality one, after a while it totally died< had to open it to get the drive itself out of it and install it to an external ssd enclosure to rebuild the file system and retrieve my data, just be careful with these Sacndisk drives.

• i still get the random disconnect issue after update with my Samsung 990PRO.

in my case with external HDD (USB powered WD passport and also a Thunderbolt RAID with power adaptor) I always had "put hard disk to sleep" off. And they both got suddenly disconnected daily.

Until recently I also had them all formatted as MacOS journaled.

Since I changed them to APSF and set "put hard disk to sleep" ON, I did not note disconnections anymore.

But of course you are all talking about SSD here and supposedly have them APSF formatted already, so that can not be it.

I suggest you run first aid on the drive. If that fails to fix the problem, erase and reformat the drive.

Update: I have not observed the disconnect problem since I upgraded to Sonoma 14.4.1. Has anyone else using that version seen the disconnect problem?

Same story with Transcend 1TB SSD (ESD230C).

Initially used for photo backups (as exFAT), but then I've started to see these "not properly ejected" issues on Sonoma. I took a risk and deleted everything to get it reformatted to APFS. After that those random disconnection issues were gone for a while, but after ~24 hours got back again.

Thought the thing is broken and was going to replace it already, but then came across this thread. I see there are very similar issues with other SSDs (and not only them - HDDs are also impacted). So that seriously needs to be looked at.

To add, the SSD seems to be fine, as it can be recognised and accessed absolutely okay when plugged in to the iPhone 15 Pro. Can't sufficiently test on other laptops, as they are all on Sonoma as well.

I have the same happening, Sonoma 14.2 but with my external HDD. I used a WD mobile drive 5TB for years and it recently disconnected more and more often, until in the end it could not even be mounted anymore. Disk utility could not fix it. I thought the drive is the problem and got a new one, now a LaCie 5TB.

But the same thing happens. It keeps disconnecting once or twice a day, even when in the middle of a backup process.

This is a major bug.

Please make sure to report your problem on feedbackassistant.apple.com as I did for my SSD problems! We only stand a chance if we mass report it, so Apple hopefully will take notice of this! Please report it! It only takes a few minutes, and it will make a difference for sure! The more reports about this, the more chances of someone noticing it!

As I said to someone else, please make sure to leave a report about it on feedbackassistant.apple.com and even maybe contact Apple Support Live Chat and tell them about your problem!

This is the only way and chance of this bug / problem ever being addressed and fixed!

Many people need to report it, so Apple will see this.

Please report it!!! 🙏😞

Has anyone ever tried to disable "Put hard disks to sleep when possible" and check, if that helps? Searched the thread, but I didn't find anything.

It may be a Mac hardware issue. I had the same thing happening 20 times a day on Monterey. It corrupted data on my external disks, fried one of them irrevocably. Apple eventually acknowledged there was an issue with the Thunderbolt ports and replaced them. Problem solved... until 3 months later when it started to come back. Rinse and repeat. Only this time Apple insisted it wasn't the ports, didn't replace them. They say it's a 'software issue' (I disagree), wiped my internal SSD and installed Ventura.

Only had it back one day, still getting to set up, haven't even installed most s/w let alone used it and ... Here we go again.

I have a similar issue since the upgrade to Sonoma on my MacBook Pro M1. Two SanDisk Portable Extreme (one 1TB, the other 4TB) cannot be used properly. A copying process of about 60GB to the 4TB SSD all of the sudden stopped. From that moment on the SSD couldn't be unlocked anymore (see screenshot). I had to buy an expensive Data Recovery Software that worked on M1 and started recovering Video Footage and copying it to my other SanDisk Portable Extreme 1TB (it was the first time it was plugged into the MacBook after Upgrade to Sonoma). Copying process went well. The next time I plugged the 1TB SSD in it would take long to load the SanDisk Unlocker, unlocked it, navigated to the folder, it would load the content of the folder (like on a ancient windows 95), load, load. Then the drive disappeared from Finder without an error message or notification. Retried a hundred times. Sometimes it doesn't disappear but it loads forever(!) and I cannot preview files. When trying to preview a file it again loads of a minute or more and than fails to preview, sometimes the content of the entire folder just disappears in Finder. It's so weird. Ive been working with these two expensive SSDs daily on my MacBook Pro before the upgrade and never had a single issue.

It's not just SanDisk. I have the same problem with a 4TB Seagate SSD. I'm concerned that some files and folders are being corrupted by this, but it's difficult to tell when the problem occurs. It's rarely while I am activity working at my laptop and most often when I return after the screensaver has come on and maybe the Mac has put itself to sleep.

I initially thought the same about my SanDisk Portable Extreme and returned it, but had exactly the same issue with both the replacement and all my other drives (la Cie and OWC, Samsung... I also previously returned the Samsung thinking it was faulty and and replaced it with the first San Disk). I was on Monterey at the time and lost a lot of data due to corruption, and a fried disk. The problem was initially resolved by changing the Thunderbolt ports on the MBP. However, it returned a few months later, so the logic board was changed and o/s upgraded to Ventura. That didn't cure it either.

Most people seem convinced it's Sonoma, but not in my case. What mac do you have? In case yr using an Intel, it's recently been suggested to me it may be a known issue with the i9 processor.