Calendar sync issues on ios and ipadOS

Hi all,

I’ve been using nextcloud for some time now as my main calendar, but I noticed some syncing issues on iOS and ipadOS devices.

Some info of my setup:

OS: Unraid with nextcloud running in a docker container
nextcloud version: 27.0.0 (issue is also present on versions 23 and newer)

I currently have an android phone running dav5x connected to the calendar (no issues there).
When an iOS device has been connected to it for some time I start to see syncing issues (calendar event changes not showing up, in rare cases this also extend to tasks).

The solution is to disable and enable the calendar link switch in the accounts setting in iOS, but that doesn’t feel like a good solution.

I think the problem is with the push setting in iOS (where data is pushed from the server to the client device when possible). The server is available 24/7 with the usual container updates, but I don’t think those updates are the cause of the sync issues. My money would be on a server config issue or bug in nextcloud that causes them.

Any ideas?

That sounds a bit like the problem I described two months ago. Unfortunately, I didn’t get an answer.

@foomep: do you also have push enabled in the iOS settings?

I think you need z-push for push to work with Nextcloud. Do you have z-push installed on your server?

I don’t use z-push myself, so I disabled the push setting in iOS and let the accounts refresh every 30 minutes (which is often enough for my use case). This works for me reliably.

Can you try disabling the push setting, set it to a time interval instead and see if this solves your problem?

Thanks @Bernie_O
I don’t know if that’s the problem. When I start the Reminder app on a device, not all entries are up to date. If I force the sync in the calendar app, not all tasks are displayed in the reminder app.
So even manual syncing doesn’t help.
But I’ll turn off push and set it to retrieve every 30 minutes and see if that helps.

As a test, I have installed the 2Do app on the iOS devices and sync via WebDAV. Not all tasks are displayed there either. I can therefore imagine that it is not a problem with Apple devices but with Nextcloud.

I think changing the settings helped. So far it’s working without any errors :slight_smile:

1 Like

Signed up just to add a +1, same problem here. And thanks for the hint about toggling the „Calendars“ button in the Calendar - Accounts - Nextcloud - Calendars, that‘s the easiest workaround for iOS.

I can confirm it has to be something with certain clients with nextcloud. I have the problem with:

  • iOS built-in Calendar
  • BusyCal on MacOS (which might as well use the Apple libraries for WebDav)

I doubt it‘s the push setting in the client, because everything is set to pull on my iOS.

It could be Apple‘s library as well, but that would need some debugging. Anything I could look for to debug the issue?

It‘s the third time sync has stopped for me, 2 times on iOS and 1 time on Busycal. It‘s happening rarely (every 6 months maybe), but can be worked around by disabling/removing and re-adding the account.

However, it‘s working perfectly fine with Android DAVx5 (the only gotcha there is that android sometimes removes permission for calendar from the app because its only a background service and therefore „never used“ but that‘s a different story).

Edit: I’ve just deleted all calendar entries in the years 2021 and 2022 and the synchronisation started working again with the 2023 and 2024 entries

Edit2: Of course everything stopped working again. See also [Bug]: Syncing (shared) calendar misses some events · Issue #36644 · nextcloud/server · GitHub