Hi @dan45,
Thank you for being patient with us. For further investigation, please share a demo account URL along with its username & password. For security reasons, I suggest you share them either in Forum DM or at support@enpass.io.
I recommend that you also try our website version of Enpass and enable the logs option in the Enpass Advance setting. Afterward, try WebDAV sync. If the error still occurs, share the logs with us.