Missing some notification and invoice emails

Hi, yes, the notifications are with confirmed, cancelled and checked out.
Having the tests I have found an issue:
After the customer made the booking and the booking is confirmed If there is a mistake changing the status and then you want to set newly on confirmed the user does not receive the notification.
For the other states (cancelled and check out) every time I change the state with cancelled or check-out the customer receive always the notification.
As I said if you change back on confirmed there is not the notification anymore.
Repeting the confirmed notification should be useful in case like this:
The booking is not paid but confirmed to avoid double booking.
There is a bank wire payment.
The customer forgot to do the bank wire
After some days the owner cancel the booking because is not paid.
Then the customer apologizes and make the bank wire.
The owner have to set the booking on confirmed again! But, in that case, there is not the confirmation email.
Could you improve that please?
Thanks a lot
My best regards