Unfortunately, Android doesn’t provide a possibility for apps to query the last sync time. In previous versions, the “Manage accounts” popup started the same activity as you can see in (Android) Settings / Accounts / DAVdroid.
If my Webdav server is having a problem and the sync fails, Davdroid has no way of letting me know that the sync failed.
DAVdroid always shows error notifications on hard errors (i.e. always except for connection problems).