StoreKit 2 Sandbox use can't buy the same subscription again

Question

My StoreKit 2 tests flow looks like this:

1. Buy subscription lvl 1
2. Buy subscription lvl 2
3. Buy subscription lvl 1

The problem is that when trying to buy the same subscription again with Sandbox user - the iOS dialogs to confirm Payment are not shown. Product.PurchaseResult in .success but if checking in Settings - the subscription is not changed.

What's also interesting: it works if changes directly from System Settings.

Any ideas of what is going on would be appreciated.