This was the one for the Google Home Mini... the fabric on the top was causing some of the devices to constantly record (there is a sensor up there that you could tap to ask a question instead of using the wake word). Once it was discovered Google disabled the tap feature.

I remember hearing about issues with Alexa also constantly recording some years ago, but I don't recall the specifics of that case enough to be able to easily search for it.

What can be asserted without evidence can also be dismissed without evidence