Dedicated servers & Port 7777

Has anyone else encountered issues getting port 7777 to open using xfinity as a provider? All the software / settings are configured properly, port 1433 for my SQL server opens just fine. I’ll be switching my modem out in the morning, currently it’s in bridged mode with a linksys router (recently acquired to rule out xfinity router) so I’ve eliminated that portion of the equation. If changing the modem out doesn’t work, I’m stumped other than changing to a different provider.