We don't use the waiting room.
We start the webinar, but do not start the broadcast. Then we run the PowerPoint slide show and tell GoTo to share that with the audience. Because we have not started the broadcast, the Attendees see the slides, but cannot hear the Panelists and Organizers talking.
When it is time for the webinar to start, we stop the preshow slides and click the Start Broadcast button.
It's interesting, thanks! I have not had such problems yet. Our company often prepare presentations for our clients. Difficulties arose with the creation of slides. I was recommended a site slidepeak.com/pitch-deck-design and I decided to consult with experts on how to make them more creative. Thanks to the advice, the presentation turned out to be successful and our business began to develop faster.