Hosting a TAK server on Xfinity

I'd like to host a TAK (Team Awareness Kit) server on a spare computer at my home for me and my friends to access. I can't get port forwarding to work at all. I am using an owned modem, and tplink router. I set the forwarding rules, but it doesn't appear that Xfinity is letting traffic in to my server. Has anyone else had experience with TAK or running another type of server at home?