One thing I am yet to try is using my old xbox one x but this isn't really a fix to play one game and if I can't resolve it I'll just give up and move on
Edit - I was able to equip items when playing on my xbox one x the problem appears to be related to xbox series x
Unsure which category to put this in my apologies.
Also I cant select operating system as xbox so again I'm sorry if submitted in the wrong place