Hmm okay, this is admittedly quite baffling!
I’ve contacted one of our Console Developers and asked if they can take a look at this for you, and if they have any further suggestions. Due to the bank holiday weekend, I may not receive a reply immediately - but I’ll let you know as soon as I have any response.
It may also be worth contacting Microsoft Support and querying this with them, in case there is any issue with your online subscription. Though I do appreciate that you’ve mentioned you can play other games fine, they still might be better suited to assist.
Please let me know if anything changes, and I’ll be in touch as soon as I hear anything.