I have looked at all the other issues that could possibly be related to my issue and can't find any solution, so here we go.
I have been working on Power BI desktop and publishing reports to Power BI services online for over a year now. I was needing to use a gateway for data refreshes until the end of last year when MS added the capability to refresh without a gateway if the data is all online. Since then I have used the scheduled refresh on several reports with no issues.
It has been a few months since I have added a new report, but this month I went to add a new report and found that I am not able to configure scheduled refreshing (it is grayed out). I also looked at the scheduled refresh configurations of the other reports and they are also grayed out. In those cases, the scheduled refresh was previously set and they are still refreshing as scheduled but I can't make any changes to the configuration.
The only issue I can see is in the Data source credentials section where there is an error, "Failed to test the connection to your data source. Please retry your credentials." There is a "Learn More" link there. There is no error that matches, but one that is close states that some data sources will not accept a test connection and this can cause the problem. This error is shown for all reports, even the ones where the scheduled refresh was previously configured and is still working. As well as the credentials work for all reports if manually refreshed using the "Refresh Now" option. The credentials being used in the semantic model come from Power BI Desktop when the report is published. For these reasons I don't think it is a credentails issue.
Other Important Information
All data is being imported. I am not using DirectQuery.
All data is in MS resources. (e.g. Sharepoint, Azure Database for PostgreSQL, etc.)
Although I am not the owner of the workspace they are published to, I am the only one making, publishing, and configuring the reports and scheduled refresh. I have always had access before. I have asked others with more access to confirm and they too are unable to modify configurations.
Any thoughts on what this might be?