Participant is getting big banner on the meeting join screen

I am using meeting-sdk to implement meeting where a host and only participate allow to have a meeting. When participant join the meeting, this covered entire page so I am using iframe for this. Things look on but as soon as Participant join the meeting, meeting screen comes and then video canvas goes back to small size and a big blue zoom banner appeared and it is giving me message that “Host has joined. We’ve let them know you’re here” even though host has already joined.

I am using sample from github

meetingsdk-auth-endpoint-sample
meetingsdk-sample-javascript