No rhinoceros licenses available

we have some issues with the rhino zoo licenses.
We have to licenses registered on the zoo service running on the server. All the pcs are able to connect with the zoo service, but even if none is actually running rhino5, the zoo says that two specific pcs are using the 2 floating license, no letting the others to connect.

First, find the computers listed as using the licenses in question and verify Rhino is Not running (Use Task Manager), or shut the systems down.
IF they still show as in use, rry “Recovering” the licenses and see if then they show up as “In use” again.
I suspect they really are in use and you may not have enough licenses in your Zoo to cover the number of concurrent uses you want.

The Zoo has a default license recovery timeout of 15 minutes. This means if a system using a license does not respond for 15 minutes, the Zoo automatically recovers the license.