Polk Audio Signa 4 soundbar occasionally makes a ringing sound.

My Signa 4 soundbar occasionally makes a loud ringing sound. This happens sometimes when I am watching something via my 2021 Apple TV 4K and then switch away from it, usually to the home screen of the ATV or the app. I can turn the soundbar off and back on again, and it stops. The sound is like an old-school telephone ring.

The TV is a Sony Bravia X90J 55-inch. I exclusively watch through the ATV, which is connected to HDMI 4; the soundbar is on HDMI, which is the ARC/eARC port.

This happens maybe 10-15 percent of the time I watch.

I submitted a support ticket on this, but wanted to see if any other Signa 4 owners have run into this.