plugin not working

I have installed the plugin and activated it but I can’t see that it is doing anything, but I may be misunderstanding how it is meant to work so thought I would check! I have created a test user that has the role of “Subscriber”. I then log in with this user’s credentials in Firefox. If I then try to log in with the same user in Chrome it logs in fine.

Should it prevent me from doing this or is it working off ip address or something only so browser session is irrelevant?

Thanks

https://wordpress.org/plugins/prevent-concurrent-logins/