I have a Power Automate Flow that creates a SharePoint Document Library on newly created SharePoint sites. This worked for many months with no problems but the last few weeks it has stopped working. Strangely, the Flow works if I log into the SharePoint site manually before running the Flow but if the site hasn't been logged into the Flow fails with a 401 unauthorized message.
I've tried creating a new connection reference on the step in the Flow but that hasn't fixed the issue.
Does anyone have any idea on how I can get around this problem? Or why it has suddenly become a problem?