I don't have time to do that today now, but I will try to look at it later. I tried Google support and the first guy was completely useless. He also wanted me to change the default setting on secondary calendars to be share all information... Sorry, but that would be a bad practice to have as a default setting.
I did find a work around while I waited, which was to go to meet.google.com and make a new meeting. When you pick schedule in Google Calendar, you can then change it to be on the secondary calendar and it appears to work. The last Google support tech told me that it's not possible to have the option to add conferencing on secondary calendars... I've spent little time with Google support, but my impression so far is it's just time wasted.