All local data lost after Davx5 Update

[DrHardReset]

Hello,

it's the third time in a year now that after an update of davx5 all local calendar/contacts data got deleted.

I set up 1 contact list and 3 calendars in nextcloud which I only sync manually once a month. So far this works as expected.

But unregularly after updates of davx5 through google play store the local data is gone. My calendar app "Business Kalender 2 Planer" does not even show the empty calendars. A resync with nextcloud restores all calendars/contacts but unsynced data is of course lost.

Now everytime playstore notifies me about an update I begin to fear.

This happened to me on Samsung Galaxy S20 FE and Samsung S25+.
The last time the issue occured with the update to 4.5.15-gplay.

Is this a known issue?

[devvv4ever]

Thanks for the report. This issue is unknown and should not occur. So if I conclude your setting:

• Nextcloud - self hosted in local network? How is the setup done? via IP address IPv4/IPv6 or hostname?
• You sync data down once. Then set it to manual sync only because you're not in the home network usually?
• You keep adding contacts/events but don't sync them right away.
• After a few weeks you open DAVx5 again and perform a sync.

If there is an update of the app in the meantime, while there are still unsynced items assigend to DAVx5-calendars or address books all calendars and address books are removed from the system but they are still switched on in the app? When syncing after everything is lost the state of the server is synced to the device (of course).

Maybe Samsung removes permissions if the app is not used regularily (there is indeed a permission setting for this on Android) and then somehow "cleans up" the device...

[DrHardReset]

My nextcloud is selfhosted in a Virtual Machine in my local network that i power up once a month. It is a bit of a legacy setup that I mainly use for backups nowadays. The setup in the app was done via hostname.

The rest of your coclusion is correct.

Samsung has this app setting option called "Manage app if unused" but I disabled it for DAVx5. I granted all permissions except Location.

[atamulis]

The same seems to have happened here.

[rfc2822]

Is this a known issue?

No (not a known DAVx5 issue) and yes (we have heard of it in rare cases, like here).

It seems that the Android accounts system is sometimes unreliable and in very rare cases removes Android accounts of an app when the app is updated. (I suspect that the app is for a very short moment "not installed" between the updates, and exactly in that moment the Android accounts cleanup runs and removes the "stale" accounts from the "app that has been uninstalled".)

As far as I know, there's no solution to the fact that the accounts are in rare cases deleted by Android (by the way also when you just boot into secure mode and back).

However, we're currently heavily working on getting the DAVx5 accounts into the DAVx5 database, so that we have them under own control: #2005

As soon as this is done, DAVx⁵ will at least re-create the Android accounts at sync, so that in most cases you shouldn't even notice the problem. (Plus a lot of other new possibilities, like backup etc.)