How do I change the install location for Xbox games??

I've been dealing with this for 2 days and I'm homicidal. I'm trying to change the install path for my games on my Xbox Ally X, and it just won't work. Every time I try, it says "You can't set your default install location to that folder. Try another one." All I'm trying to do is move the XboxGames folder into the Program Files folder.

I've seen hundreds of others posts about this, but there's no definitive answer or solution and none of the suggested fixes work. I've tried it in the Xbox app and inside the Microsoft store, neither work. The Microsoft store doesn't even give me an error, just lets me select whatever folder and then does absolutely nothing.

Anyone have any ideas? Truly driving me bananas.