Hi, I have a couple of questions that might help you determining the cause and/or have a solution to this problem.
My solution was achieved by checking all those steps, some might sound stupid, but you'll see where I'm getting.
I'll bring it in form of a short Q&A, please try everything from top to bottom before going straight to what solved it for me at the bottom:
Q: Have you checked the sensor of your mouse and your mousepad
A: Ofcourse yes + extra argument: this issue only happens in game.
Q: Have you installed all the latest mouse, gpu, chipset, etc. drivers and changing mouse polling rates and mouse acceleration?
A: Checked it all, I know what I'm doing here.
Q: You turned off CPU intensive background programs?
A: Yes, I still have the issue after closing all background processes possible. (task manager and stuff...)
Q: You turned off SMAA, FXAA, V-SYNC in game or even ran the game settings on the lowest and worst possible settings?
A: Jup, it maybe felt a little better to play, but the problem is still present.
Here it might become interesting for you:
Q: You have a descent CPU, 'good' RAM (memory) and a quite recent high-end GPU?
A: Yes, lost my money because of that expensive hardware. I even got an NVME SSD!
Q: Is your OS or game installed on that 'NVME' SSD?
A: Yes, They both are.
Q: What if you move your game to a normal (SATA) SSD or other disk?
A: I moved the game to an other internal HDD or other normal (SATA) SSD, but the problem is still present.
Q: Have you also tried to install your OS on a drive different than the NVME?
A: FIXED IT!
Basically, I have quite good hardware;
i5-6600K (best i5 CPU in 6th gen), 16GB RAM at 2133Mhz, MSI GTX 1080 Gaming OC, MSI Carbon Z270m MoBo, Samsung NVME 960 PRO 512GB, 2x Samsung SATA 850 EVO 256GB in Raid 0 config, 2TB HDD, Logitech gaming gear: G810, G502, G933, 2x 1080p 60Hz monitors at the sides and a primary 1440p 144Hz monitor, all over DisplayPort)
This config should work properly out of the box without any BIOS changes or OC. However there might be a bottleneck somewhere with these guys: CPU, MoBo and NVME SSD where some mouse input doesn't get registered or is delayed.
After a good year and a half or two with this build I had a total of 3 clean installs (just because I'm a geek and I like it clean but can't always keep it like that).
The first time I installed my OS on my NVME; I had those mouse stuttering issues only in some recent games, switching the game from storage drive didn't help.
The 2nd time my OS was installed on the Raid 0 SATA SSD's (which could be a single SATA SSD for you): This was the smoothest and best performing time, I did long with this Windows installation. I had no mouse stuttering in game. The game however could be installed on the NVME, HDD or Raid 0 SATA SSD's and it all ran perfectly. Problem FIXED here!
After that I tried to install my OS again on the NVME. Guess what, the problems came back exactly as before.
I just reinstalled my OS on another drive now, and my problem is again fixed.
So if you feel yourself being in the same situation as me, and you don't have any other way out to solve this, and are ok to spend 50 to 100 bux for a normal SSD if you don't already have, try installing your OS other than on that NVME, and install your games on it afterwards.
If you tried this, please let us know if this helped you out.