SharePoint Modern Doc Library Web Part - Won't display other views

This looks old, but not an old problem for us that we found issue with and resolution for.

When adding a Document Library Web Part to a modern page, we were using 'Group By' View to organize some Documents. Having the documents grouped didn't cause the issue, and initially displayed the group by documents view accordingly in the web part, initially.

Long story short, when we expanded a specific sort group that contained a file without an extension, we would get the error. (so initially it did not crash when collapsed). For any of you, that data may already be visible? 

"The specified list is invalid
The specified list might have been deleted or you might not have permission to view it. Contact the site owner for more information."

When we found the file that didn't have an extension (maybe since we are managing content types), and removed it from that particular group and expanded, the error did not persist.

When we expanded the group sort where we placed the file, the error displays.

In short, check your files and their extensions if you are managing content types.

Cheers.