Offline Device not Signed Out

I received the Sept 8 breach email and promptly changed my password and signed out all of my devices. I then went to each device, and logged back in, except for a Roku stick that I only use while traveling. When I powered it on and launched Plex, it was signed in already. Makes no sense to me unless there is some need for devices to be on within a certain period of time for the session/token to be invalidated? How could this offline device that had not been powered on for months log right in after singing out “All Devices” three weeks prior?