How to port foward for assault cube?

[Toriality]

Hi im having problems with port fowarding in AC. I`m able to open ports in most games (i tried GMod and minecraft) but for some reason AC doesnt work.

Thats my setup:

( private IP  |  protocol  |  internal port  |  external port  )

the error in cmd prompt:

[SELECT ALL] Code:

looking up ms.cubers.net:28760...
Status at 02-06-2020 14:44:31: 0 remote clients, 0.0 send, 0.0 rec (K/sec); Ping: #0|0|0; CSL: #0|0|0 (bytes)
WARNING: master server registration failed: failed pinging server

also: when I enable DMZ the server runs normally, but since it's not safe, i prefer to leave it disabled

---

edit:

Jahoo in discord helped me, making 2 separated rules for 28763 and 28764 fix the problem.