calendar is slow to respond after update to ios 15.1 on iphone XSmax

I have found if you toggle your Wi-Fi on and off this will temporarily fix your calendar issues… Until Apple opens up to it and comes out with a fix

For me upgrading to 15.2 on my iPhone13Pro did the trick.

Exchange agenda activated and iphone agenda still works normal.

Bug was fixed with iOS15.2 on iPhone 13pro. Calendar now works fine.

Is it still happening with iOS update 15.2 , i think most of the people got it fixed with new update

Worse issue on iPhone 13 pro, Calendar app is not usable with large Google calendar account - it lags and crashes.

Please all affected people do also write a feedback in order to increase the chance of a timely bug fix by Apple https://feedbackassistant.apple.com

Im experiencing same issue, calendar freezes, boots me out, etc. I’m running both Exchange and Yahoo calendars on my iPhone. I thought it was Exchange as well because of all the security measures we implement every few months at our college, ACL changes, etc. I turned off WiFi and that seemed to fix issue… we’ve been testing WiFi vendors as well. Got home started getting same problem there as off home WiFi. Seems toggling WiFi off/on seems to temporarily fix issue. Restarting iPhone does nothing… and I would not reset networking settings on your iPhone as some have suggested, all it will do is wipe out all your WiFi network logins, etc. It may well be an issue with the new IOS syncing with Exchange, toggling WiFi seems to temporarily fix issue… Apple needs to step up and address issue.

having the same issues and no response from Apple on any of these long-standing issues. I just added Google Calendar aps to my iPhone and iPad, they work really well, have no lag in updates and both have better UI than iOS native apps.

As a software team lead this seems to be some major bug in how Apple calls data over the network, I logged into the Apple iOS Health app and it took 5 mins for the app to update milage for a long hike, and the mileage was completely wrong based on map and fitbit. Wow MANY fails Apple

I am having the SAME Issue. I use multiple calendars and they are all mashed up. The only solution I have found that refreshes them properly is to shut down and restart.

[Edited by Moderator]

Thanks - I just upgraded my iPhone 8 to his 15.2. This sorted my problem with the calendar on my iPhone...

Seems to be fixed in 15.2.

I contacted Apple via the Support app, pushed to get to a Senior Advisor and they called me. Collected a screenshot and diagnostic logs and said they would get back to me in 48h.

I'd suggest you all do the same so they can narrow it down more quickly.

Same issue and even worse on iPhone 13 pro: Calendar app not usable with large Google calendar account.

Issue exists since update from iOS 15.0.2 to 15.1.

I have written a feedback report to Apple, and sent in the required iPhone diagnostic report.

Please all affected people do write a feedback in order to increase the chance of a timely bug fix by Apple: https://feedbackassistant.apple.com

Apple Support in the Netherlands listened to me and found multiple reports of the issue, so for sure the issue is recognized now within Apple as related to use of the Calendar with an Exchange account.

The only suggestion was to see if removing my Exchange solved the issue, which I refused as it makes no sense to test with an empty Calendar.

There is no solution yet.

Why is this marked Solveed?

If you're having this issue, please, report it to Apple via the Support app on your phone. This is the best way for them to see the impact and ensure they have all the right logs. Push to get the case bumped up to a Senior Advisor.

Yep, same problem here. I have multiple synced calendars. As far as I can tell, it is just a different presentation of the same problem that has always existed with synced calendars. When you first open calendar after not being in it for a few hours, it does a sync. Previously, this manifested as the calendar jumping up and down in dates as the data populated. Now, it seems like it takes the same amount of time, but instead of jumping around, it just freezes or causes extremely laggy performance.