I bought Valhalla for my girlfriend a few months ago to play, and over time it has proven increasingly unstable to the point of being unplayable. She can't play more than a couple minutes before the game crashes, or often on start up it'll crash before even in the game proper.
It is only Valhalla that's crashing. I've played and beaten Spider-Man: Miles Morales, FFVII: Remake, AC: Origins and AC: Odyssey on the PS5 without a single crash.
I bought the PS4 disc copy of the game, and have tried several times to delete the game entirely and redownload it, making sure the game and system is fully up to date, restarting the console, booting into safe mode and clearing the cache and rebuilding the database. I've tried being logged in/out of Ubisoft Connect.
At this point I'm at a loss of what to do. She really likes the game but it's unplayable now.