iOS 10 exchange calendar sync issue

I did a quick follow up test. On corporate wifi I created six different calendar events, four (not in sequence) went through, two did not. The third and sixth never show up in Exchange. Turned wifi off and did the test again and for once all six showed up. On LTE I then went and DELETED all of them on my iPhone. I got four out of six to delete. Each day has two wonky ones left over. So still screwed up. No difference between LTE and WIFI. Just darn inconsistent.

Has anyone found a better calendar to use instead that works with Exchange on the iPhone? I have not found a good alternative. This one is becoming unusable with it being incorrect 90% of the time. I never know if I can trust it.

There is a work around you can try that has enabled me to make ones that don't work show up (and you could annoyingly just do this for all of them as you enter them until it's fixed)-- after creating the item, go in and edit the time to something else. Save it. Then go back in and edit it back to the correct time. This has always worked for me when I noticed one not on exchange. Note: It has to be the time that you change. I've tried just adding a character to the title and it doesn't work.

Interesting. But problematic as I make the apts when I'm away from exchange. So by the time I'm back at my desk a few days later I don't recall every mtg I setup to know to go back and check them. Especially if they are months out. I appreciate the ingenuity though of finding a method to force the update.

Without the external connection nothing will sync at all after the initial download of adding the account for me. It won't even add the account over Verizon for me. So it may be to related, but different issues. It is very strange since everything syncs except the calendar over Verizon. I do have a question of them blacklisting anything on the specific phone number in to our Verizon rep. Then again, it could be a problem with the iPhones that Verizon is peddling too. If I can't get this solved I will most likely just port the phone number over to another provider and see if that solves the problem permanently.

This worked for me

Fixed MY problem and this is how:

Settings -> Mail -> Accounts -> [Select affected account] -> Turn off Calendars -> "Delete from My iPhone" -> Confirm Calendar cleared -> Repeat but turn back on

This forced a resync and the phantom meetings did not return for me.

I confirm I have the same problem where deleting a single instance of a recurring event from my iPhone does not sync to the Office 365 server.

But also, often when I created events in my Calendar on my iPhone these events do not sync to Office365. It does not do this for all events, but I have noticed that if the event I'm booking overlaps with another event in the calendar, then 90% of the time the new event I created on my phone will not sync to Office 365. If I create a calendar event that does not overlap with any other event, then it syncs to Office 365 fine.

Thank you LAegis, This calendar syncing issue has been the worst issue. This issue that occurs over and over again and I support a very high profile client Missing an appointment or a meeting set up on his outlook calendar set up by his assistant (who uses outlook for EVERYTHING) is a total disaster. After attempting everything i read on the net, only this fixed Calendar syncing issue. Not sure how long it will stay updated so keeping my fingers crossed since Apple doesn't seem to care to provide a permanent fix to this.

I am having the exact same issue. Items on my exchange calendar are disappearing on my iPhone which is a major issue since I use my phone as my main calendar reminder to be in the right place at the right time. It's a serious problem for me. I tried removing and adding the calendar back in, turning my phone off and on, nothing is working. Now I have even less appointments showing, it's like it deleted them all. I'm exceedingly frustrated.

I have the same issue. I can see my Exchange Office 365 calendar on my ipad but not syncing on my iphone. someone please help!

Same here, hope it will be fixed asap

I have an issue that is similiar but the Calendar app completely freezes up on my iPad Air. I can't view events without waiting approx. a minute or so then they will pop up.

Yeah lost sync with both calendar and also unable to retrieve emails now, doesn't matter whether this is wifi or cellular.

Yeah I'm finding that new events in my iPhone 6 Calendar app don't sync back to the Exchange 2010 server, and new events posted using Outlook 2016 don't show up in my iPhone.

I would like to avoid switching to Outlook app for iOS but I will if that's the only workaround (at least for now).

Or maybe this is an incentive to get people to try out the Microsoft-written Outlook iOS app!

Anthony Maw, Vancouver, Canada

Same problem here. I can add new meetings in all calendars on my mac and iPhone and they are synced with exchange. But when deleting a meeting with an invitation on my mac it is not synced to my iPhone. The meeting is still there. Other meetings are no problem when deleting. So the problem is when someone is invited and afterwards the meeting is deleted.