In your example, RemoteDBClient can not log into the server (401 - Authentication failed.)
In v1.14 there was no problem.
How to agree login between the server and the client?
How do I login RemoteDBClient to RemoteDBServer?!?
This is a regression. RemoteDB 1.15.1 release today to fix that issue.
You can use middleware logging middleware to log requests processed by RemoteDB server: