This is the expected flow. If the host closes the browser or gets disconnected, another user will become the meeting host and the meeting will continue.
When the host rejoins the meeting, they will become the co-host.
My Case little different No participants in the call(on End), When Host Close Browser means Livestream not getting End. That particular Meeting ID not getting Webhook Response. We need find those Meeting ID , and want to end Manually using API call. Its not possible to do every time, until manual work we cannot start use those user is free or not.
And In this case no one want to rejoin as Host.
Please consider this as a serious issue, We had to brought more user to overcome. but That not possible to inverse that much amount for unused Users
A possible work around for you is to use the Participant Left Webhook, check to see if the user who left or closes the browser (disconnected) is the meeting host, and if so, call the End Meeting API. That is a completely programmatic solution.