It is a silent timeout. No error messages. We have tried both regular ware houses and serverless. The App has access to both ware houses. The ware houses started up. 

"If that's not the issue, you could also confirm that the SQL Warehouse is UC enabled. Or, the networking path between the App and the warehouse might be restricted somehow -- maybe try connecting to a Serverless SQL Warehouse as a test."

This may be an issue. Let me look into it.