I'm relatively new to the forums and I am trying to fix an issue I've been having the last few days. Seemingly randomly, my S8+ starts to make a knocking sound. It usually starts when I am wearing my bluetooth headphones, and keeps going through wired headphones or the regular speaker once it starts. The only way I can reliably get it to stop is when I restart my phone, but that is only a temporary fix. I have read that some people believe it is tied to the NFC but I always keep that off. Any ideas on how to fix this?