Multiple transaction id

[Executable]

Hello, 

 

I added a custom gateway using Mastercard payment and everytime I'm making a payment i have a double transaction every time.

I don't know how to debug it and how to fix it. I commented out the following function in the callback: 

//checkCbTransID($transactionId);

WHMCS : 7.9.0

I'm using mercanet as Gateway (https://documentation.mercanet.bnpparibas.net/index.php?title=Connecteur_POST)