Office 365 products try to save to SharePoint rather than OneDrive

[paulkaye]

This behavior began recently, I believe.
If I open a Word, PPT etc. file that resides in my OneDrive, if I then use save-as, the location presented for saving is the SharePoint "equivalent" of the initial OneDrive folder. For example, if I open the file:

C:\Users\Paul\OneDrive - [redactedFolder1]\[redactedFolder2\document.docx

when I use F12 to save as, or when I click "publish to PDF" the folder presented is:

https://[redactedTenantName]-my.sharepoint.com/personal/[redactedAccountName]/Documents/[redactedFolder1]/[redactedFolder2]

This is annoying at the very least, but also causes some strange downstream behaviours. For example, when I save a Word document as a PDF, my browser is prompted to open a sharepoint url and download an(other) copy of that PDF to my browser's download folder.

In case it's relevant, I'm using Microsoft 365 (from my business) on a Windows 10 PC.

Any idea what's going on? I just spent over an hour on the phone with Microsoft, with no success.