I have sent the latest beta version via email to check if the problem still occurs with it (there have been related changes).
Keep contacts/calendars on device after deleting davdroid account
Is it possible to keep the synced contacts and calendars on the device after deleting the davdroid account?
perfect would be a dialog which asked for keeping information on the device on account deletion.
No. All contacts and events are deleted by Android when the respective account doesn’t exist anymore. If you delete an account, export the data before.
It might be possible to set the “owner account” of the contacts/events to
at.bitfire.davdroiddirectly, but I don’t know if this will even work and can’t recommend to do so as it would be non-standard usage with undefined results.