Getting isModerator() value intermittently onConferenceJoined event, lib-jitsi-meet


I have created custom conference UI using lib-jitsi-meet.
I want to show some controls only if joined user isModerator() , I am checking this on onConferenceJoined event and setting state. But I am getting isModerator() true intermittently , even if user is moderator. Is there any delay in setting moderator role at backend?
Where(Jitsi Event) should I set Moderator role so I will get isModerator() true if he is moderator always.

Thanks in advance.