Schedule Webinar in a Zoom Room

What role will the Zoom Room have in the webinar? Attendee, Alternative Host, or Panelist?

Also, what are you using as your calendar service for the Zoom Room (Google, O365, etc)?

This info will best inform next steps.

For me it works when adding Zoom Room as both co-host and as a panelist.
It's also mentioned here:
https://support.zoom.com/hc/en/article?id=zm_kb&sysparm_article=KB0066116 

I don't know about your setup, but you might want to try do calendar integration (however looking at how quickly webinar join window showed on my ZR console, it's probably not related).

But if that info was misleading and you don't need that to be a webinar, but just a simple meeting, then that's something different. In that case I'd advise you to do calendar integration for sure. When you schedule a meeting in Zoom, Outlook window should pop up. At that point you can either:

• add e-mail address associated with that Zoom Room as another attendee in your mail invitation (however that would make it less obvious where the meeting will be held)
• select appropriate room as a Location - but that will only work if you have your Exchange properly configured

I'm assuming there, that you are using Exchange/M365 as your mail/calendar service.