Duplicate ticket with collector

Hello !

I manage rt 5.0.3 on debian 12 with mysql and postfix.
I have an email address that is used as a collector to create tickets on rt when sending to this address. I’ve noticed that when I send directly to the e-mail address (TO) in question only one ticket is created, but when I copy this e-mail address (CC) two identical tickets are created.
If anyone has an idea I’d be interested, as I don’t understand how this is possible.

Thanks in advance,