Quoting dng@??? (dng@???):

> I do not have experience with Zoom but with Jitsi and discovered that
> disabling WebRTC leakage in Firefox because of WebRTC leaking ip
> addresses also crippled Jitsi.

The first comment on this bug is said to address that (even though the
bug report is for the standalone Electron-based Jitsi Meet client,
'jitsi-meet-electron'):
https://github.com/jitsi/jitsi-meet-electron/issues/324

In short, yes, what you observe is correct, but you can accomplish your
objective by blocking WebRTC leakage using the block-WebRTC-leakage
feature of the uBlock Origin extension, rather than using the similar
feature in Firefox's about:config .