iVMS-4500 only working locally via wifi?

Hi guys, I’ve been wrestling to setup a couple of hikvision cameras to a ds-7604ni NVR and have ‘almost’ got them working by updating the NVRs firmware. Things are fine locally and working when connected to wifi. However when out and using iVMS-4500 I can not view? The alert notifications are coming though but no video feed.

Can anyone please suggest what I should try?

Many thanks,

Devs.