Unable to open any ports since going fibre.

[#1]

Hi, I have had a 4 camera dvr networked for several years with no problems, I switched to fibre and it still worked ok, however I have since changed my dvr and find that I am unable to open ANY ports on the router which is the technicolour TG582n with an openreach modem.
I have spent weeks trying out every configuration in the book including the suggestions that I have found on this forum, anyone help?

[#2]

I'll take that as a NO then.

[#3]

Might be worth buying your own router. The PN one is free for a reason