Databricks Queries NOT Hitting Databricks

[sarah_riecke]

I have a report published in the service that connects to Databricks. 

About a month ago we were getting a timeout error, BUT the queries sent from databricks weren't hitting the serverless sql warehouse. We updated the warehouse from serverless to pro, and this seemed to solve the problem for about 3 weeks.. That was until a couple of days ago (the details below are also what we encountered 3 weeks ago before switching from serverless to pro). 

In the am (UTC), we have adf pipelines that kick off to refresh out data in databricks, and then refresh Power BI. 

But with the latest error, we can see the refresh kick off in Power BI, but it tries for 2 hours before failing. (4 times at about 30 mins each - trying to connect to Databricks). 

If I go look at the monitoring of the sql warehouse for the past 24 hours (in which the power bi failure happened), there is nothing that shows up, so the queries aren't even hitting databricks to spin up the sql warehouse. 

We had about 3 weeks of successful refreshes via API but then suddely the same errors again, and nothing changed on the power bi side. 

But when I try to manually refresh later in the data, the refresh succeeds, and it goes through just fine. Initially we thought that other workspaces within the org were using serverless capacity, and that is why we initially changed from serverless to pro, but now we are seeing the same errors with pro again. 

I have tried looking for other solutions out there, but haven't really found much. I'm not sure why in the morning during the scheduled API refresh it won't even hit databricks from power bi, but later in the day it will with a manual refresh. 

Edited to add:
SQL Warehouse Details