Bob was referring to leaving no connection for Pin 1, like you have already done.
What are you using for the BFD’s output? I’d suggest a XLR/RCA cable like you have for the input. Don’t know if it’ll make a difference, but it can’t hurt.
Failing that, I’d suggest getting back to the basics: Disconnect all source components from the system, and then re-connect them one at a time. Typically the offending piece is a cable box or satellite receiver.