How to update local calendar files?

[p2ww]

I have a few calendars that I maintain as ICS files and which I would copy to the phone, either by adb push or file transfer. Since I don't update very often and am happy with having them as read-only, it seems to me that this is the use-case for the "pick file" functionality of ICSx5.

However, I have not found out how to actually update the ICS files. Whenever I copy a new version of the file, or even edit it from within adb shell, the content:// URI seems to be broken somehow and I get an error message from ICSx5 ("Couldn't open file from storage" in red).
As a workaround I can then add a calendar with "pick file" again (using the same filename as before!), force synchronization, and then see error message disappear. (If I then do not remove one of the identical calendars, Etar displays both...)

Am I doing something wrong? Or is this a bug? This is with ICSx5 2.0.2 on LineageOS.

[p2ww]

To partially answer myself: I updated to ICSx5 2.0.3 a few days ago, but also the OS on the phone. Since then updating the ICS files using adb push works as expected.

But when I transfer the files from the (Linux) computer using USB file transfer (by mounting the phone), the calendars are broken as before. Not sure if that is expected or a bug. Since that is the way I would prefer (I don't think it's wise to leave ADB activated all the time), I'd still be happy to help track this down, if somebody told me how.