[Bug] Reinhardt Crusader Fire Perk inconsistent bug

Reinhardt’s new Crusader Fire Perk reads:
“Refund a firestrike charge when you stun an enemy, overfilling up to 3.”

This works both with earthshatter and when you pin someone with charge (The moment you pick someone with charge).

Now here’s the buggy and inconsistent situation:
[1 charge available 2nd one charging]
IF your 2nd firestrike charge is charging up and is less than 50-60% done and you stun someone you will not get an overfill that continues charging up to 3.
You will not get an extra charge overfilling up to 3, instead it will fill up to 2.

IF your 2nd firestrike charge is charging up and is up more than 50-60% done and you stun someone you WILL get an extra charge and the remaining charge will continue to charge up overfilling up to 3.