Schedule Refresh not working

I have published a PBI report and data set to my workspace in PBI service.  The dataset and report can be refreshed manually but I have set a scheduled refresh which does not work at all.  I get no error messages.  My sign in credentials must be fine as I can do a manual refresh.  I have also updated / edit my credentials.  My two data sources are in SharePoint, one is an excel file and the other is a Microsoft List.  I have cleared my cache.