iPhone no longer works with going from Meeting Room to Meeting

I have an acquaintance who has an iPhone 12 running system 17.51.

She has meetings with a "coach", and Zoom works fine on her computer, and it used to work fine on her iPhone until about a couple of months ago.

Now, when she's in the waiting room, and her coach tries to let her into the meeting, the connection "gets lost."  She isn't being told "Goodbye" and that she's being logged out, she just seems to lose the connection.

Anyone have any info on this issue?

Thanks for any help!