Loyalty & Rewards - Voucher went to another customer

[NIKESLB]

Hi. This is not first time but  sometimes a customer is converting points to a voucher and another customer have access to it, but can't use.

1. Customer A generate a voucher from point
2. Customer B will see check his vouchers and verify that there is one to use
3. Customer B try to use this voucher and give an error, because it's not associate to his account

 

I can't understand why someone else can see a voucher from other customer. Any idea? May compatibility between cart rules, but the  module integrated with prestashop doesn't have this option.

Edited January 30, 2018 by NIKESLB (see edit history)