After one year using an eight cam system with embedded wifi (XmartO-like), I decided to try another system that allows me to use my own router and computer, different cameras and, consequently, is more flexible/offers more features. That’s why I bought Netcam Studio (16 sources).
I’ve been playing with it in order to get familiarized with its options before I install the new wifi/onvif cameras and start using Netcam as my cam system. I can say Netcam is exactly what I was looking for and the only prob I found so far is related to remote access. I’ve read all messages about similar probs, FAQ, visited suggested links, to no avail. 
I use a Cisco DPC3925 (voice-cable modem/router) in bridge mode connected to a D-Link DIR-868L router. The computer running Netcam is associated to a static IP, port 8100 is forwarded to it and all I get is “Login failed: Timeout has occurred” on Netcam Android and “Error during login: …http://201.x.xxx.xxx:8100/Soap… InnerException…” on Windows client (running on another computer).
I set the modem to router mode, connected Netcam Server computer to it via ethernet cable, forwarded port 8100 to its IP, without success.
In both cases, I even put Netcam Server computer in DMZ and the same prob.
I also connected Netcam Server computer through my mobile network (hotspot) and all the same.
I tried Netcam Server on another computer.
I Checked Windows Firewall thrice (no other firewall installed).
On the other hand, if I use Netcam’s local network IP, both clients work fine, which means the prob has to do with external connections.
Well, as you can see above, I tried all the basic steps to solve de prob. At this point, the only thing I can think about is my cable and cell providers’ CGNAT. Is it possible port 8100 is blocked on their side? I don’t if it helps, but it’s worthwhile to say I have no probs with Hangouts, Telegram, Whatsapp, Skype, etc.
I thank you in advance for any idea on what’s happening with Netcam remote access in my environment.