Port forwarding kinda works?

[SirSquid]

I have an actiontec mi424wr rev i router that my ISP is forcing me to use because they installed a MoCa connection to my router so i can get TV too.  When i try port forwarding on it  only kinda works, all the port forwarding checker websites say my ports aren't open but on my TF2 and unturned server people can join for a shorty while then they get kicked off due to a networking error.  I've tried updating the router's firmware, change the ports im trying to forward, factory resetting my router, changing the router's firewall to "minimum security", changing the server's static ip, and i also tried putting one of my servers in a DMZ and that did nothing. Also this is happening on both my dell poweredge 1960 iii and my poweredge 2950 ii so i don't think that's the problem.

[Enderman]

is this a modem or router

if its a router than its plugged into your ISP modem which you also need to port forward

the easiest way is to not use routers and plug the system directly into the modem

[SirSquid]

26 minutes ago, Enderman said:

is this a modem or router

if its a router than its plugged into your ISP modem which you also need to port forward

the easiest way is to not use routers and plug the system directly into the modem

Its a modem router combo and i already tried putting it in bridge mode to use my own router but it refused to go into it.