File versioning not working in Document Library

I'd very much appreciate some feedback here before I pull the last of my hair out!

I have a document library. Versioning and check out is enabled. Major versions only.

I'm using the native 'Version' column, but it just stays empty, despite the document showing as Approved in the library

As a test, I created a new document library, enabled versioning, check ins and approvals and uploaded a file. Even after approving, the version number doesnt show

I have tried getting the meta data from the file before and after to see if that will update the Version but it doesn't work. Any help would be greatly received!