I normally let other people handle the Sharepoint troubleshooting but have an odd one.
In an organisation, links are emailed back and forth all the time. The links are used to open Word documents primarily in app.
One user on one computer has an issue. Sometimes the links launch Word but instead of opening the target document it opens a blank page with the long reference string as the title.
Sometimes closing it and re-opening it will make it work, other times I am advised it continues to fail for up to an hour.
If the link is copied and pasted into a browser, it opens the document in Word Online without issue
I'm not up on the mechanisms that Office uses to translate the reference string to know whether this is an Outlook issue (trying a new profile and awaiting feedback), a Word issue or a SharePoint issue (I suspect not as the user can log into their laptop and hasn't seen the issue).
Example showing Word with the reference string in the top