@rfc2822 Thanks for you attention to this issue. I got it to work. Uninstalled both apps, rebooted phone, reinstalled both apps and now it is working. Must have been some hiccup that needed a reboot to clear out.
I’m using DAVdroid 1.6.5-play on my Samsung Galaxy A3 (2017) with Android 6.0.1 to synchronize Calendar, Contacts and Tasks with nextcloud 12.0.1.
Every time I close the OpenTask app manually, all tasks are gone. Then DAVdroid starts to synchronize for minutes while the tasks slowly appear again one after the other.
I already reinstalled the OpenTasks app and DAVdroid.
Here is the debug info (repeating entries shortened - original file over 100 MB size): 0_1502727707032_davdroid-12077-20170814-172503.txt
2017-08-14 17:26:25 15 [syncadapter.TasksSyncManager] Downloading 1175 tasks (30 at once)
so that 1175 tasks have to be synchronized every time. If you want this to scale, I suggest to archive finished tasks somewhere else.
It looked like a DAVdroid problem in the beginning. Later in the day I noticed, that closing the OpenTasks app causes the problem somehow.
Addition: Not just every time I close the OpenTask app manually and open it again, all tasks are gone. This also happes by itself after some minutes. Then DAVdroid starts to synchronize them again.
I already reinstalled both apps. Serveral times.
I’ll delete or archive the finished tasks.
Thank you so far.
If there’s any specific indication that this could be a DAVdroid problem, please post it here.
Another phenomenon today: All tasks twice in OpenTasks app. They all disappear again when I close it. Then synchronization as usual…
Problem solved. It was the OpenTasks app.
SOLUTION: In the permissions settings of the OpenTasks app the option “Contacts” (in german “Kontakte”) has to be turned on.
Thanks for your help.