Cannot activate Parallels with valid license key after Mac Repair

I purchased a Parallels 11 key and used it successfully on my mac already. Unfortunately the logic board of my macbook had to be replaced (apple defect). After the repair Parallels requires to be activated again. When I enter my license key I get a green tick and the prompt that it is already in use but I can activate it for this mac -> after I click "Activate for this mac" it says that the maximum number of activations was reached - I thought this action would render the old activation invalid and force-activate for the current computer / hardware.
In "My Account" I don't even see any subscriptions (which just cannot be true as I already used Parallels 11 with this key for half a year) and if I try to add it, it says "The key you entered is not a valid key. Please make sure you have a valid key and try again or contact Parallels Support Team for assistance."

Could someone help me resolve this issue as it is really frustrating not be able to use something I have paid for just after repairing my mac.

 

Problem was solved by Parallels support - thread can be closed