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

I prefer to use the agenda view, it allows for fast viewing of multiple days via scrolling, but that view now seems to have the worse staggering, delays, skips, and hesitations. Which all defeats the purpose.

Read somewhere to delete calendar app and re-download it. This definitely helped with the overlapping meetings when changing days. The list view still staggers and eventually freezes when you go about a week into the future. It’s much better though, but still seems like an issue that was never there until 15.1.

I’ve been to the “genius” bar three times and they have no clue on what’s going on. The first time they replaced my iPhone 12 mini. The second time they told me to erase my phone and the third time I was told literally that “it is a little laggy but it still works.” I told the “genius” that it was an answer worthy of Microsoft. I’ve seen this issue posted all over the web, so now I know that it is not my issue. I hope they fix this as it is very annoying for people who use the iPhone for work. I’ll wait for a patch but in the meantime I’m getting an android to test it.

The point about the Android is that I have never tried it. I hear how IOS is so much better, but that may be a thing of the past; besides I am now curious of how bad it is when half the world uses it. You would expect some type of support from Apple for an expensive device that’s still in warranty. This lagging issue is in several threads around the Apple Forum and the web.

I have the same problems, very laggy and the wrong entries are showing. I tried switching to the agenda view and scrolling was very slow. On switching to the agenda view it took me to April 2020 and when scrolling through to today I noticed all the entries for my work calendar that has lots of entries and recurring daily entries were showing. I have the sync set to only go back 2 weeks so I would assume that any entries older than that shouldn’t be displayed. When I remove my work account in the calendar using the Calendars option at the bottom the performance in the agenda view is fixed and scrolls smoothly.

Maybe the sync period is not being honoured and it is causing more data to be used than necessary. The sync definitely worked because I had to change it earlier this year to check on some older entries. Worth checking Apple?

From my point of view I can deny any theory, sync period might the cause.

My default setting is ever since 2 weeks and I always just sync'd the calendar from one business Exchange account, so in words one calendar ever since only, not more. No change on that since roughly 12/13 years now.

What ever it is, it is not usable anymore after update to iOS 15.1, Apple has to fix that. Putting hands on a crystal ball just confuses everybody ...

I agree, but having addressed this with Apple multiple times, I can tell you that they are in denial. I hope that someone addresses the issue though. I have too much stuff that I have purchased but I’m so ****** that I’m considering Android.

Don’t know what Apple is thinking of in refusing to comment on this, lie to people at Genius Bar refusing to discuss the issue. I have moved all my iPhone and iPad apps to Google and hut off Apple access to analytics for Mail, Calendar, Maps …

There was a post in REDDIT about some sort of virus. I tried to go back to post the link here but I could not find it. Don’t know if it was deleted. If someone finds it, please share it. It seems our data is compromised. It also mentioned that it also affects many other apps like Chome for IOS. I don’t know if it is true, as I tried to go back to it and could not find it. I asked our IT guy and he was not aware.

I don't think this is really true.

When I switched my iPad and iPhone Calendar and Contact apps from Apple to Google apps everything works perfectly. In the iOS apps at first view, everything is incorrect (wrong dates and events) and slowly the calendar will update, the data is all there with the correct metadata. It's a network data pull issue (sloppy code, no regression testing)

This is simply really TERRIBLE QA on Apple's part.

As a Tech Lead / Program Manager with 15+ years experience, this is inexcusable. Apple tells people to restart devices, delete apps and re-install them. As one other commenter put it when told this at "Genius Bar", I would have expected that nonsense from Microsoft, not Apple. Sorry Apple this is a #fail

In addition, the iPad home screen widgets are also screwed up in 15.1, photos not available, cannot add new ones, again sloppy coding

I have had the same issue. Based on what others have said here I removed the exchange calendars from my phone and the calendar is now working perfectly. I still have a POP email account and that calendar works fine. I still need those exchange calendars for work so I hope Apple does a new update to fix the issue.

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.

Sorry my message got cut off. As a temporary solution you can call on Siri to pop up your calendar and enter meetings or view your day or view your day. It’s not the permanent solution but it will get you through until Apple fixes this hopefully soon

I have the same issue across all of my iOS devices and on macOS. The issue started not right after the software update but just recently. Basically, I'm not able to use the calendar app at all. When I open it on macOS it starts consuming 100% of CPU until I force quit it. On iOS devices, it constantly freezes and crashes.

I didn't try resetting accounts, deleting them, etc. as I don't see it as a part of the solution.

I have this problem as well on both iPhone 12 & iPad after upgrading to 15.1.1 - that said, I discovered today that it only happens when I'm on WiFi. If I'm on cellular, there's no problem. Not sure why the difference. Doesn't matter what WiFi network I'm on (home/work/public). But I've started to turn off my WiFi on my iPhone when I need to access/view the calendar. Not ideal, but a workaround until Apple can fix this with the next software update.