I had a generic DVR which has the same IP as the new one. When I plugged the new one in it worked fine. Nothing changed apart from me adding new cameras, then suddenly I couldn't access it while out on 4G.
Now I can ping it from a machine that is wired to the router, but can't from anything that is connected to the wifi, even though it has the same IP range and can ping other devices on the network. It also doesn't work when trying to access via my external IP.
But, I have woke up this morning and it seems to be working, nothing has changed over night. I can pretty much guarantee it will stop working at some point.
Thanks,
Aaron