How do I free licenses?

I have a server with public web application with Unauthenticated access and there seems to  be a problem that CSP session ends, but associated license persists for some time (hours). If several users log in, we can hit license limit and all the other users get 503 Service unavailable error.

We are currently debugging it and moving to authenticated web applications,  but is there a way to free these licenses quickly?

Here's how it looks like in SMP: