It seems Sync Location (WebDAV) settings do not survive Backup/Restore.
(I had my iPad replaced earlier today)
I needed to re-input them. Consequence: full resync engaged as far I can tell.
I assume this is by design (Encryption passphrase to decrypt remote DB) but a alert message toward user is definitely missing here.
Suggestion: keep WebDAV address, user/pwd and ask for Encryption passphrase again.
Or… is this a bug? (DTTG 2.2.1 on iOS11B8Dev)