Occasionally, DAVDroid produces error notifications reporting a failed synchronisation attempt, throwing a “NoSuchElementException”. The stacktrace indicates a problem with the okhttp3 library which is apparently unable to find a “healthy connection”.
Forcing a synchronisation manually afterwards causes no trouble.
I cannot provide steps to reproduce this error, as I couldn’t find how to trigger it on purpose. Nonetheless, here is the debug log: https://paste.gnugen.ch/raw/xZiP