Random noises from _muted_ participants

I'm often in a team meeting with a dozen participants. Normally after each person speaks, they go on mute. However, there appears to be a bug that is triggered by going on mute, that random blips occur, which sound like repeated audio frames from the next person to speak, until the previous person unmutes and re-mutes.

We're all on Mac (except one user) and are normally pretty up-to-date (centrally managed, currently all on 5.17.5 (29101) but it's been going on for ages).

I've not been able to find out if this is a known bug or not, as searching for this issue comes up with a lot of random unrelated problems.