I did not configure, but noticed such behavior of PlaySMS. And it would be more logical to add this notification method, instead of the above. Because in fact the user is blocked, and the notification that comes out does not notify about this, and this in turn leads to substitution. I think this notification method needs to be added and it will be correct.
Thanks for answering about the number of attempts.
What about the notification? Can I make a warning instead of a notification that the user is locked?