Firewall DMZ vs Port Forwards

[Noob question]

I have a server running on my network. During setup I opened the DMZ and pointed the Host IP to the server. Everything works fine (inside and outside.)
Now that everything is up and running I’d like to close the DMZ and use GL-i Port Forwards.
So I add the port Forwards, (disable the server ufw,) and close the DMZ but then no connections work.
(If I disable Port Fwd and open DMZ all works)

Am I missing something?
Thanks for reading.

Server: Ubuntu 18 (with ufw enabled 22,25,143,80,443,3306,8000/tcp)
GL-I AR750, 3.105