CCTV DVR and it's software program stops communicating

[videobruce]

I have a CCTV DVR (Speco Tech if that matters) that uses a software program to connect to a PC. There are two basic modes; Live TV and Playback. Both functions are pretty much self explanatory.
I was having issues with the 1st unit I received (new) but that one did NOT have this issue. The 2nd one did. No changes on my end, thou I did update the F/W in my Router (running DD-WRT). I reverted back to the F/W version that was in the Router, but NO change. Problem remained.
I uninstalled the software and re-installed it, but no change. Rebooting the DVR makes no difference. I contacted the manufacture (US based support for a change), but they claim none of their units do this (of course), but they did point a finger to the PC (of course, it couldn't possibly be their fault) which I was waiting for them to do that. Except for the fact the 1st unit did NOT have this issue, it had numerous others not related.

If I just open and run the program without changing the 4 camera view, all is fine, data continues to be sent, but when I choose any specific camera, then return to the 2x2 (Quad) view the data stream just dies out and the images are frozen. If I click back to any single camera the data may return, but it usually dies out after a minute or so. Closing the program and re-opening it brings it back to square one.

I use a program called 'Bit Meter' (similar to DU Meter) to continuously monitor LAN & WAN status as to data flow in and out. This is how I determined it was a data flow issue. (I have used one or the other of these for well over a decade, great troubleshooting tool !!). The max data xfer rate is 10Mb/sec. thou it's usually around 5-6 Mb/sec.

Now, to add to the mystery; if I change to 'Playback', the problem seems to go away (AFAIK). Data flow is back and it doesn't seem to be affected my any actions I do.
I don't know if the software used a different port between Live View and Playback, I believe it's the same. That was the only area that may explain this that I could think of.

Details;
Static IP addresses !
Win 7 Pro x64,
AMD based Gigabyte MB, FX8350 processor, 8GB of memory, wired Ethernet,
NO A/V or local Firewall programs running, no suspicious processes or services running. I use ProcessHacker (poor name choice), it's a superior substitute for Task Manager).
This does install MS C++ 2010

Any ideas out there??

[videobruce]

The software is here (but you have to register to d/l);
https://www.specotech.com/secureguar...ital-download/

The DVR is here;
https://www.manualslib.com/manual/28...vx.html#manual

[videobruce]

The replacement arrived and now the connection drops with the Router after 20-30 seconds after rebooting. It's done it 4 or 5 times. And the connection never returns. The activity LED's on the Ethernet port on the DVR both show active (and I have changed the cable).

The question is; is there anyway that a Router would reject or 'time out' a active device either with a static IP or a DHCP address?? Or for that matter the device itself? There are no conflicts that I know of, this isn't a huge Network, usually5 or 6 devices active at a time.

Someone here must have a idea?

[Jonj1611]

It's not really my thing to be honest, I would hope someone might have an idea though!