Using CCTV Via DVR with Fibre

[#1]

Hi
We moved over to Fibre a few days ago for our business.
Previous Router was the Technicolor TG582n which we successfully set up to receive CCTV pictures remotely from our Swann Camera system using the Netviewer Ap. .
We now have a Sagemcom 2704N Router which goes to the main BT Socket via a Openreach Engineer installed Huawei HG612.
I can access the TG582n to make the Port Forward changes (UDP/TCP) to open Ports 85, 9000 and 18004.
DMZ has been altered to assign the device.
It works on the internal computers connected through the 2704N Router but I have run out of ideas to set up mobile or remote devices.
I can only think that the Openreach box is causing the block. This unit has no user available settings that I can find. (Login 192.168.1.1 does not work).
Has anyone else had this issue, or am I missing something obvious?
Help would be appreciated as we are in a fairly rural location and not having remote cameras is quite a worry.

[#2]

Try using grc to see if your ports are open https://www.grc.com/shieldsup

[#3]

A port set correctly would look like this.

[#4]

Thank you.
This was my result. (If the picture shows)

[#5]

Try the (lookup specific port information) tab to see if port 9000 and 18004 are open, port 85 appears to be in stealth, are you trying to put those devices  in DMZ ?

[#6]

If you are after port triggering/Nat try looking here 192.168.1.254/expert_user.html

[#7]

Well, I have deleted the old router settings (Port Forwarding), retyped them in and have assigned the DVR to DMZ and it seems to have solved the problem.
Now accessing internally and on my phone nas ipad through my mobile network.
I still don't actually understand what happened, but it works!!
Thanks 1110_110 for your time  

[#8]

I have it happen to me now and then with the 2704n, seems like a glitch with port forwarding for some reason, as you just said... try again
I don't hold with DMZ being a great solution though, glad you have it working.