Error when activating license on same domain

I’ve had this issue a few times now so wanted to make sure I wasn’t doing anything wroing, or know if maybe is just a common issue.

The error occurs when for some reason the licence has to be re-validated on the same domain.

I enter the key but the server returns the error: “Reached maximum activation. License key already in use on cliendomain.com”

My guess is that the license key might be in status “Active”, and that’s why it says it has reached maximum activation, but I think re-validating the same domain shouldn0t cause this issue.

I’ve ‘manually’ changed the licence key to ‘pending’ and removing the dmoain validated, hoping that would make a difference, but I still get the same error.

Is there like a cache thing that I need to reset or something to recognize the key as pending and validate the licence?

Any ideas are very apreciated.