Activating Device on 4g

Hi, I hope I have posted this is in the correct forum, so apologies if I haven't. I have 2 cameras attached to my account. 1 doorbell, 1 stick up cam. When I use wi-fi I can view my live feeds fine, but the moment I go to view them on 4g, it just says activating device and doesn't load the stream. On 4g I can download at 40mb and upload at 10mb, so that's not the problem. Any advice would be greatly welcome. I'm not sure if this is an easy fix or a common problem.