Describe the bug
Opening any powerbi:// endpoint fails with "The following error has occurred while updating the connection: An item with the same key has already been added."

To Reproduce

1. Open DAX Studio v3.0.10
2. Connect.Tabular Server.enter endpoint

• Log shows: Establishing connection
• Sign in
• After 60s or so:
  The following error has occurred while updating the connection: An item with the same key has already been added.
  Error selecting database: one or more errors occurred.
  Error setting selected database: The connection either timed out or was lost.
  Error connecting to server: xmla endpoint 

If I repeat these steps, I still get the "same key" error and the model browser is blank, but I can write and execute queries against the model. Advanced.View metrics does not work: "Error viewing metrics: the database ' ' could not be found"

Additional context
The endpoints are in the msit environment