I know that you are not at the origin of this problem
I think that Softorbits are not really serious. I’ve tried with firewall and antivirus disabled and the result is still the same: activation error key already used. 2400 activations they say..ok but where ? If activations are restricted to some countries it may be a reason of this problem. Not solved for me at this time.
I got other software from this editor and it is necessary to allow access when activating and after done to disable any access to internet, and then the activation stay enabled. I discovered this way to do with Softorbits software one time before with activation of “Background remover” was lost without any reason.