I just just performed a re-install of the Plex App and uploaded the logs here: Fire TV not Advertising as Player; Cannot connect from remote/companion app - #7 by f15hb0wn. I remember there being an “Advertise…” option in older versions of the player app. With that missing, could it be the newer installations have defaulted to having “Advertise as player” as off with no way to enable it? If so, it would explain why my older FireTV devices running the same version of software on the same network allow Remote control (I must have enabled it before the option was removed or it was defaulted on).