Power BI Service - Data Set Refresh Fails - Data source credentials greyed out

To the PBI Community,

I have developed a PBI file which uses data from API sources and which includes three tables imported from my local machine. The API sources all use basic auth and all use the same credentials. Privacy level is set to Organizational for all. The three excel tables have been set to not refresh and I've played around with having Privacy = None, Organizational and Public. The file refreshes in the PBI Desktop without issues, but as soon as I publish and try to refresh in the service, I get an error message prompting me:

• Data source error: Scheduled refresh is disabled because at least one data source is missing credentials. To start the refresh again, go to this dataset's settings page and enter credentials for all data sources. Then reactivate scheduled refresh

Then the "Data source credentials" options in the settings page is disabled (greyed out).

Again, this file needs to automatically refresh on a schedule without needing to access the files on my local machine. I thought by excluding the local tables from refresh, the service would not consider them.

1. Is there a way to get a more granular diagnostic from the service, e. g. to isolate which data sources are causing this? I would like to confirm that the problem is with the local files - even though excluded from the refresh.

2. Should I simply recreate these Lookup / Fact tables in the PBI Desktop using "Enter Data"? Would that solve the problem? 

I do not wish to install a gateway and make the file dependent on access to my local file system. 

Thank you,

Henrik