Loud noises since last update

Having an issue with loud cracking noises, seemingly after a firmware update. It just repeatedly makes a loud crack. When using an android phone, it appears on the doorbell itself. When using the Echo Show, the cracks are only heard on the Echo. Got a new doorbell but having the same issues. Searched the internet, German sites as well as English ones, for any other users having issues lately, but couldn't find anybody. Am I alone?