Possible memory leak in the videocall plugin

Hey there.
I’m facing a rather suspicious situation.
I keep encountering the error “Username %some_username% already taken” intermittently, despite having definitely terminated previous sessions for this user. So I attempted a simple solution: assigning a unique username every time a user attempts to register. While this resolved the issue, it subsequently caused the janus memory usage to continuously increase without any limit. The only way to resolve this is to restart Janus.
So I think that videocall plugin does not reclaim memory at some point.
Folks, do you have any ideas what it could be?
The error is here, but I can hardly guess what it could be

You’re probably not cleaning up sessions/handles properly.

I’ve double checked: I remove the handle, then destroy the session. The only thing that I keep is WS connection to Janus - I share it between all the sessions on a single application node.

Also, there is a session timeout of 3600