Intermittent failures when creating new libraries in modern SharePoint

Hi everyone,

I’m seeing an issue in our modern SharePoint Online site collection where creating new document libraries has started failing. This site has worked normally for years, but over the past week, most library creation attempts haven't worked. 

1) The page briefly flashes or glitches during the creation process. 

and

2) A non‑ending spinning wheel when I hit "create"

or

3) Creation attempts return “Something's not right.” error page. 

The failures happen across all subsites, in multiple browsers, and I’m a Site Collection Administrator. No permission changes were made recently.

Has anyone seen similar intermittent library creation failures in a modern site collection, or know what might cause this kind of inconsistent behavior? Any guidance would be appreciated.

Thanks!
Meagan