Remote management of TP Link behind Hub One

[#1]

I've setup my TP link as a DMZ device on hub one, and set port forwarding. I can actually authenticate to the device over 4G or other internet connection using fixed public IP, but once authenticated, I get a screen with just an empty rectangle, like a picture placeholder. I was always able to manage remotely pre-hub one. It's an Archer D5 TP link. Any thoughts?

[#2]

I think that this is unwise even if it isn't one of these: http://seclists.org/fulldisclosure/2017/Feb/22 .