Hi,
Looking at your print screen it look like your outside your Wi-Fi but connected via VPN.
I did some testing and have the same resutlt, but it works with DMSS, have you tried that instead?
My overall impression of DMSS is that it's way better for playback and event managing than gDMSS.
On the other hand, gDMSS is better for quickly taking a look at the cameras, as it can autoplay the latest viewed cameras - which DMSS still is not capable of.
gDMSS
Connected to wifi - works, snap available
Outside wifi, no VPN - doesn't work
Outside wifi, VPN connected - doesn't work
DMSS
Connected to wifi - works, snap available
Outside wifi, no VPN - works, snap available
Outside wifi, VPN connected - works, snap available