I’m not a big tasks user (I had a dozen entries that… most I never got to heh) - but they did sync.
I noticed when having two apps that manage tasks, I can’t get the Tasks items sync to the remote through built-in accountmanager (the fork) or davx itself.
Doesn’t matter if the pair is opentasks + tasks.org or opentasks + jtxboard. The default Tasks (opentasks fork) will not sync. It also lost the Tasks permission so the content resolver complained:
ContentResolver: Failed to get type for: content://com.android.calendar (Unknown URL content://com.android.calendar)
There’s something I don’t understand yet about tasks in Android (I do know that they’re just calendar entries, funneled into a caldav object by am/davx).