I’m 99% sure it’s a bug.
I have filled in my connection string and when I click “test the connection” i get
“Your connection string does not fit the standard string. It should look like mysql://username:password@my-db-instance.endpoint.us-east-1.rds.amazonaws.com:PORT/db_name.”
When I remove the # (hashtag) in my password I get
“Connection issue Connection attempt failed: Login failed for user ‘REMOVED’.”