Rhino 6 keeps showing "license is being used on another computer" while that computer is shut down

On computer (A), I am prompted, like every 5 minutes, that “the license is being used on another computer” (B), and every time I would click “Yes” and it will fetch licenses from the Cloud Zoo. However, the “another computer” (B) isn’t turned on at all. Besides I have tried to launch and exit Rhino on that computer (B) but the situation didn’t improve.

I thought the license is not correctly returned to the Cloud Zoo but I can still use Rhino for about 5 minutes continuously on the computer (A). I do not have this issue with Rhino 7 installed on the same computer.

Any ideas?

Figure:

image

But ILLUSION-DESK is nowhere in the usage history.