Anonymous I have copied your questions & added my corresponding answers in blue:
1. Are there a specific few reports that are experiencing slow refreshes or errors or are they all affected? Do they correspond to the same data source or different data sources?
This is affecting all reports. My colleagues who work on Power BI reports are also experiencing these issues. The reports correspond to several different shared dataflows which seem to be refreshing as usual, and which have not been changed since we began experiencing these issues.
2. What data sources are associated with the reports that are having problems?
This is answered above. The data sources are dataflows which are properly built & have not been changed. They simply reference SQL servers.
3. I see in the screenshot that there are a couple of refresh errors, what are the specific error messages?
Refer to screenshot below for the error message: