HomePod makes random thunking/popping sound when idle.
This started happening around OS 13, now on version 14.3, on one of my 4 Homepods. No amount of resetting, unpairing, Home app removal/rejoin has resolved it. Read about others with similar, and worse, complaints. Might not be software related as other Homepods on same network seem fine at the moment, and it only happens on the one side of a stereo pair..
Of course, these are out of Applecare now and thus would cost more to repair than to replace. Had it less than a year. I can barely live with it, but guess I'll have to. Wanted to chime in here to add to the frustration that appears to be mounting.