On-prem data gateway "credentials invalid" with two data sources

Hello,

I have a dataset with two data sources - one is an excel file on Sharepoint on-premises, the other is a SQL server.

I am using an on-premises data gateway - when refreshing I get an invalid connection credentials error.

I attempted some troubleshooting by separating out the two data sources, and individually, they both refresh fine using the on-premises data gateway.

Has anyone encountered this issue before?

Thanks!