Failed to update data source credentials: Azure DevOps: 500 - Something went wrong!

Hi,

I have a report that worked fine & refreshed on schedule up until 2 days ago (no changes have been made to the report).

It has 2 data sources:

- SharePoint

- AzureDevOps

SharePoint authentication works fine but the ADO (AzureDevOps) connection gives me an error. The refresh works fine in Power BI Desktop but it doesn't refresh anymore in Power BI Service. Has someone encountered this issue before and found a way to resolve it?

This is the message I get in the Power BI Service is an HTML source code that looks like this:

If I put the source code into a browser it renders like this:

It says:

This operation is not supported for a relative URI.

Failed to update data source credentials: Azure DevOps

Other notes (not sure if it matters):

- this is in a premium workspace

- I've tried authentication by logging through OAuth & by creating a personal access token as well. Same error message.]

Thank you for your help in advance.