Continuous popping sound of homepod

I have two homepods set up in stereo. One of them started popping more than a year ago. At the time I did hard resets, and other solutions brought forward on these threads. There were some threads of others that thought it was a hardware issue, so I unplugged the one and waited for apple to come up with a fix. One of the recent threads shows that it should resolve with software update, which i did and after that and hard reset, still a continuous popping sound which changes up and down with the volume. Does mine have a real hardware issue?