Me too, playing on Xbox S and X consoles via disc.
Xbox GamerTag: Blueschill
Same exact problem and symptoms as op.
Playing from UK.
This happens not only on my Xbox One S but on my Xbox One X also, game gets to loading screen, music distorts (it sounds like it is still playing but it's very slow and distorted), xbox becomes unresponsive and shuts down my xbox after around 10-50 seconds of being on the loading screen.
NOTE: Interestingly both xbox's cannot be turned back on and restarted via its controller, power button must be pressed to restart.
Happens on the last mission discoveries only, every other mission works perfectly, Multiplayer works perfectly and daily card collection and claiming system works perfectly.
Worked for 20-30 seconds initially first time, now will not work at all, have tried mission resume, select mission and loading by finishing previous mission.
No dvr or cortana turned on, or background programs running in background.
Tried fresh install, clearing local save, reducing resolution, wired and wireless network, factory reset! (Which I'm not happy about) lots of smaller changes like changing video settings.
I was really enjoying the campaign as well, I'm really upset about this as nothing seems to work to fix it.
I have never had a campaign that is totally unplayable before.
We need some EA assistance to look into our accounts.
Nothing works.
If this a problem with discs then we need a free digital install source that can be validated with our discs.
If this is a problem with the game as a whole this needs to be patched once and for all as I have read many other reports of this problem.