New, consistent refresh failures

yamyam1 The suggestions so far all come back to re-entering the credentials, and your first sentence already says you did that across all four spreadsheets and the error persisted. I'd treat that as information rather than something to repeat, because a credential prompt can only fix a credential, and there's a documented way to break a file-based source that no amount of re-authenticating will touch.

Microsoft's data refresh doc says this about files hosted on OneDrive or SharePoint Online: "You can move the file to another location (using drag and drop, for example) and refresh will continue to work because Power BI still knows the file's item ID. However, if you copy that file to another location, a new instance of the file and new item ID is created. Therefore, your Power BI file reference is no longer valid and refresh will fail." That distinction is sharper than it looks, and it's the reverse of what most people check. Moving a spreadsheet is safe. Copying one is not.

So the question isn't whether the files moved, it's whether any of the four quietly stopped being the same file. A Save As over the top, a new version uploaded rather than edited in place, a restore from the recycle bin or a backup, a library or site migration, someone rebuilding the sheet and re-uploading it. Every one of those produces a new item ID sitting at the same path, so it looks completely normal in the browser while Power BI is still holding a reference to something that no longer exists.

Two things worth pinning down before you change anything else. Which of the four is actually failing? With four spreadsheets it's easy to spend an afternoon re-authenticating three that were never broken. And your own title says new and consistent, which is a useful detail rather than a throwaway one, because a token or throttling problem tends to come and go, while a reference pointing at a file that no longer exists fails every single time in exactly the same way. Consistent fits the second one better than the first.

When did the first failure land, and does that date line up with anything being re-uploaded, restored or migrated on the SharePoint or OneDrive side of things?