June 2021
Was there ever a resolution to this problem?
August 2021
Bumping.
June 2022
Rediculously, about two years later we finally have an answer. And it is both blindingly simple and completely baffling.
If you've had this problem then chances are you've not assigned a profile picture to your xbox account on the series x.
Simply go to your profile, assign any picture and the game will now load without any problems.
No idea why the profile picture caused such an issue but nice to finally have a resolution.