OK its unlikely to be a game specific issue if it happens to other games in addition to NWN. Do you get the same problems on wifi and wired connection and (I know this one is a bit of a stretch) if you can test with somebody else's PC in your house or alternatively try logging in somewhere else (go to a free wifi place?) that might help narrow down where the problem is coming from.
I'll try to do these in order. I tried to do a "/netgraph" and "/showfps" but I guess I'm an idiot - I couldnt get them to work - NO idea what my ping or latency is. AT the Server Screen, the server pings were 67, 63, and 53 (1,2,and 3)
Modem Factory Reset: I changed the admin password, network names, and network passwords back. (5G and 2G) Looking for the QoS settings, I went thru EVERY Menu screen on the Modem.
I'm sorry people on Arelith have problems. Of course, Arelith is on NwN EE, AND I only have the ONE computer. SO scratch the multiple PCs on the same network theory. (That usually IS where you end up having to forward ports and stuff - at least it was like that when I ran 4 copies0 NO multiple accounts now.
Strangely enough I run BOTH with the Wireless AND Ethernet connection at the same time. The cable modem sits on one side of my desk, and the wireless router on the other side (right next to the computer). The tech said to keep them apart from each other. He also recommended using both connections simultaneously. That has been working just fine since we moved here months ago. I don't use the Wireless 2G connection at all. (my neighbors like to borrow it when their cable gets shut off - lol)
I will plan on testing with JUST the ethernet and JUST the wireless to see if that has any effect. I may even cut off the neighbors in case something they are doing on my 2G is messing with me. They are heavy gamers (Skyrim). Last time I looked they had 1 PC and 1 PS4 connected.
I would LOVE to be able to try a different location, but that would mean packing up my desktop and 42" screen. Not something I am eager to do, but something I may end up having to do anyway. of course, i think I'd head to one of my kids houses rather than Wifi spot. We'll call that close to a last resort for now. Whenever you move an entire desktop you tend to invite problems. At least that's the way it goes sometimes - Murphy's Law and all. But it may come to that.
I very much appreciate the suggestions even though it may look like I'm just bashing them. I spent my career in computers and if I know anything, it's that sometimes computers just "do whatever they want to". lol I fear I may never find it, or when I do fix it I won't know what I did, or it will just wait to go away on it's own someday (not very likely)
But at least I know now that I have the Single Player game for when withdrawls get to be too much! hahahaha
I gotta go play with my network connections for a while now - lol
It is something weird that only affects multiplayer games.
As an alternative thought, if your router supports it, you might try putting the computer into the demilitarized zone. If your issue clears, then it is a router setting, if not, it is the PC. Not a lot of help, but it all I can offer ATM. I strongly recommend not leaving it there unless you have some serious onboard security.
The computer must be on either wifi or wired as they can't usually access both at the same time, I have both on my desktop machine and it defaults to wired unless something prevents this working in which case it switches to wireless, to be honest I doubt that's where your problem is but its good to try and eliminate as many possible locations of the problem. Based on all your comments so far I'd be focusing on the connection kit although I just have an 'as supplied by the ISP' one piece modem/router and I suspect you don't have spares to swap in and test, I've got a big box of old kit for similar reasons although my better half keeps trying to make me dump it!.
Another thing that comes to mind especially with the latest upgrades/updates from Windows 10 build 1903: Check your motherboard and lan drivers. Could have happend that they got kicked out and causing the issues now.