Why does a subscription get transferred to another user?

1. Have user A logged in
2. Purchase a subscription
3. Log out, log in as user B
4. Purchase a consumable in-app purchase

Expected: no subscription for user B, subscription for user A

Actual: subscription for B, no subscription for A

This is extremely wrong, since user B is expecting to get a consumable in-app purchase effect, while they get an effect as if they bought a subscription. Subscriptions should only be transferred when explicitly asked by a user.