I just checked that from my Ubuntu Advantage subscriptions, there is 3 machine connected to my subscriptions. The problem is, the only machine that actually use the subscriptions only 1. I don't know the other 2 machine, I am afraid that the 2 subscriptions slot are allocated to the past Ubuntu VM which is already deleted.
I would like to remove the 2 unused machine from the subscriptions slot, but it seems there is no menu from Ubuntu Advantage dashboard, and I cannot delete from the machine either as the VM is already deleted long time ago.
Is there any way to re-claim the 2 slot?