First two participants in a conference needed to reconnect in order to hear another participant

I organized a call today from 10:30PM EDT - 2:30PM EDT. I was the first particpant and M was the second. Although I chatted with several participants and everything seemed to be working fine, when I called on a participant K to speak neither myself nor M could hear K. However, several other participants reported that they could hear K. So I went into my URL bar and hit ENTER to reload the page and I asked M to leave and then immediately rejoin. The workaround succeeded as M and I were then able to hear K.

Is there a bug in the transition from 2 to more participants where some audio streams can get disassociated from the first two participants?

Do you have information about the browsers that were used on the problem sides and their versions?

I am using Chromium 83.0.4103.116-1~deb10u2 on Debian Linux 10.4 (Buster). I think the user M was using an iphone or ipad, but I’m not sure.