Yep, same here, no solution yet.

My beam was doing the buzz thing when turned off. Some other forums recommended updating the “simple link” setting, which I did and it stopped. But then LG updated the software and it started again. 

^ just a push to bring back the topic. Mine is still doing it, with various degrees of intensity and frequency: nothing for a week, then twice in a day, loud or very quiet… How can we proceed to bring more information to Sonos ?

Your best bet would be to submit a system diagnostic within 10 minutes of experiencing this issue, and contact Sonos Support to discuss it.

I usually suggest the phone folks, they have more tools available, but are only available Monday through Friday during business hours. Twitter support folks are available 24/7.

There may be information included in the diagnostic that will help Sonos pinpoint the issue and help you find a solution.

Just had the issue, diagnostic report no. 613591025.