I had to change my password for my webdav sync. Everything works fine in Devonthink Pro Office, but DTTG keeps failing to snyc. I have tried to find where to update the password, but I can’t find a place do this. Help please.

You need to clean the Sync Location and reSync afresh. Right-click the Sync location in DEVONthink’s Preferences > Sync and choose Clean location.

Did you change the encryption key or the WebDAV account’s password? In the first case it’s indeed necessary to clean the location, in the second case it’s sufficient to update the sync location.