@jimsalter @lattera oh god I think I just remembered -- I think it's socat because I wrote an rc script for it for FreeBSD and I naively added a "reload" option and was shocked to see it kill the service

from its man page:

sighup, sigint, sigquit
Has socat pass signals of this type to the sub process. If no address has this
option, socat terminates on these signals.