Sync stopped working on Android 6.0.1

[peterpanther]

Hi there,
I am using ICSx5 V. 1.8.6 on a Sony E2303 (Aqua) with Android 6.0.1(German language version). Yes, this is outdated, but it worked fine until 4 weeks ago. Now it stopped syncing both my calendar subscriptions (one is an ics with login credentials, one a url to a shared webcalendar).
I have not changed anything to the setup on purpose and followed the threads here regarding that issue. ICSx5 is exempted from battery optimization. But even a manual sync from the calendar app does nothing.
The app is not stored on the SD card, actually it is not possible with that Android version to move it to SD. I deinstalled and reinstalled the app from F-Droid without success. The subscribed calendars are correctly recognized, but the status in ICSx5 remains at “not yet synchronized” (i.e. “noch nicht übertragen”) for ever.
Any leads what could be wrong are appreciated. Thanks a lot

[peterpanther]

Sorry, need to correct myself. The ICSx5 Version is 1.8.7

[rfc2822]

Hi,

Have you used the so-called “stamina mode”?

I think this is related to Sony. Do you think it’s an ICSx5 problem and why?

[peterpanther]

@rfc2822 No, I followed the advice here and switched stamina off. Unfortunately, I have no clue what might cause the problem. But I did not install or change anything on my phone since ics5x stopped synchronizing (about 4 weeks ago).
So for the moment I am asking for more tricks I could use to revive the synchronization with icsx5.

[rfc2822]

Ok, maybe someone with Sony has ideas… unfortunately I don’t know why this happens and what you can do…