I was having some issues with brief lag spikes in Overwatch online gameplay (with NordVPN closed).
I used PingPlotter (pinging google.com every 0.5 second, NordVPN still closed) to analyze my connection and found lag spikes every 70 (68/69) seconds (not sure if they are timed like in Overwatch yet, will see later since I fixed it).
I have Intel Dual Band Wireless-AC 3160 M.2 as WLAN adapter. I first tried a possible registry change that disables background scanning for networks, but this did not help.
When I tried to adjust adapter options (first IPv6 off, this did not help) then I saw NordVPN Lightweight Firewall in adapter options and turned it off. This resolved the PingPlotter lag spikes.
Does this option in the WLAN adapter affect NordVPN function? I did not even have NordVPN launched during all of this and I imagine NordVPN may be dependent on its own virtual adapter and its options?
I hope this information will help anyone else who still uses similar hardware and NordVPN.
Edit: Problem returned once strangely. To be sure also disabled that background scanning again (just google adapter name and background scanning). But still believe this issue related to NordVPN since it was an immediate fix. Connection is stable now.