In this version 10.2.1 setup is a little different, you first need to set default options, your serverURL is a URL (domain) and setRoom would be your full url. Something like that:
val defaultOptions = JitsiMeetConferenceOptions.Builder()
.setServerURL(URL(https://meet.jit.si/))
.setFeatureFlag("pip.enabled", false)
.setFeatureFlag("welcomepage.enabled", false)
.setFeatureFlag("invite.enabled", false)
.setFeatureFlag("call-integration.enabled", false)
.setFeatureFlag("calendar.enabled", false)
.setFeatureFlag("raise-hand.enabled", false)
.build()
JitsiMeet.setDefaultConferenceOptions(defaultOptions)
val options = JitsiMeetConferenceOptions.Builder()
.setRoom(https://meet.jit.si/AliveObsessionsCreditFreely)
.build()
JitsiMeetActivity.launch(context, options)
So, setRoom is not about nameRoom only, but about domain plus idRoom. It needs to be unique. To change the room name, use #config.subject= at the end of the url.