Hi, yes. I hope this helps you out.
Basically there were too many requests to SharePoint that resulted in throttling and eventually failure with HTTP response 429 Too Many Requests.
I had initial queries that imported the data from SharePoint, however I then had subsequent referenced m-queries that worked off the initial imports. I could see with Fiddler that although the these queries were referencing the initial SharePoint imports, they repeated all of the original SharePoint calls again. I even had a few places that referenced-a-reference of an initial query, which compounded the number of calls even more. What should have only been <80 SharePoint calls was now in the 1000s. I did not realize at the time that a referenced query in desktop m-query does not always reuse the original query (even with disabled parallel loading of tables).
I reduced the number of calls two different ways. Fortunately one report uses a premium enabled workspace so I able to setup a dataflow for the initial SharePoint calls which then eliminates the subsequent referenced queries that duplicated the calls over and over. This was actually a very easy copy/paste change. I had another report where dataflows cannot not be enabled, so I ended up rewriting the subsequent m-queries that repeated the SharePoint calls in DAX.