activation after new installation

I had to reinstall Trados Studio 2019 on one of my devices (laptop). The setup is completed and is now showing the test version. However, I am using Studio 2019 Freelance Plus. I believe, I need to return 1 license meaning deactivate it and re-activate it.

I am not able to deactivate one of the licenses neither online nor offline. 

I am also (under: Offline deactivation certificate) not able to "Generate Deactivation Athorization Ticket" 

What do I need to do? Thanks for any help.

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