Well i contacted my ISP they said opening the ports is not something they do. Which isnt very helpful, as from looking online this is a big issue, affecting lots of people.

@TP-Link my ISP told me that a public ip address was not available. I did enable upnp and also dmz, both never made any difference. I will see if I can get them to open ports at there end

I hope someone can help. I have Archer MR600 (eu) Ver 1.0 which has O2 sim card, as I live Scotland in a place that fibre is not available, maximum speeds of 1mbs down, 0.5 mbs up. Have to use RE650...