Bank validation notification cancels the purchase process

Here in Europe, some banks are requesting a 2nd step verification to confirm a purchase (especially if it’s the first time the user order something with its Google Play account)
This verification is made thanks to the customer’s bank app.
The process is the following : when going through the process to purchase something (a subscription in my case), before the purchase is validated and before the Google Play bottom dialog is closed, the user’s phone receive a notification from its bank account to confirm the transaction,
BUT sliding the top bar to see the notifications and tap on the one coming from the bank app IS CLOSING the Google Play bottom dialog.
Then validating the transaction didn’t transform the purchase from a “pending” state to a “purchased” state.
How do I have to handle this case??
Thanks!