Saw this on the Support page however I am still having issues since last week. Screenshot from today (6/6 @ 2:50PM PST). I am unable to make any query changes/refreshes to my SharePoint list due to credentials failing.
"Power BI Desktop customers may experience authentication issues attempting to connect to data source using AAD and may see the following error message "We're unable to connect. Please delete your credentials and try again later". The fix has been published to the downloaded center with the standard release of Power BI Desktop."