Did you have any luck with support? I'm having the same issue. Even more strange is that the ever changing table that pops the invalid query locator refresh error doesn't have Salesforce as a source. The table source is a reference to a base table. Only the base tables queries Salesforce. How can a table that doesn't query Salesforce cause a Salesforce error? Something isn't adding up.
Refreshing from desktop and republishing works in getting updated data to PBI Service. However immediately after publishing I get a yellow triangle error in PBI Service beside my dataset that says my refresh failed despite the last refresh date being only moments prior.