Shared computer and Windows Store : Purchases of second account not taken into account

Hi guys,

Here's the description of a very akward bug. Let me give some background.

My friend and I both have a Windows Xbox Game Pass, with our respective microsoft accounts. Let's call our accounts a@outlook.com (for me), and b@outlook.com (for my friend).

We both play in our respectives houses, on our own computers. My friend purchased a DLC, and I purchased another DLC.

My friend comes at my place from time to time, and when he connects to his account on the Xbox App, and then launch the games, he does not have access to his purchases, but to my purchases.

Steps to reproduce :

1. With an account A, on a computer A, buy a DLC on the Windows Store
2. With an account B, on a computer B, buy a DLC on the Windows Store.
3. With Account B, On computer B, launch the game at least once.
4. With Account A, using the computer B, no matter which windows session, launch the game.
5. As Account A, you can't access your previous purchases (step 1), but you have access to the purchases of account B.

In other words, my friend can't play his own survivors and killers on my computer. But he can play mine. Weird.