Question Odd stuttering issue without an fps drop in oldschool runescape

[lowbudgetlobotomy]

Just built a new rig with the Intel i3 10100 @ 3.6ghz, 8GB ram, gigabyte b460m ds3h
Windows 10 64bit

I only play one game and its oldschool runescape which relies heavily on cpu and barely any gpu at all, so I did not buy a discreet graphics card - I am using the integrated Intel UHD 630 to connect 2 monitors, 1 vga, and 1 dvi.

A very annoying issue I am having is absolutely 0 frame drops in the game yet a very noticeable coming and go (seemingly random?) choppy stutter, like the monitor can't keep up smoothly or something, its very odd. the game maxes at 50 fps and it doesnt drop even to 49 throughout any of these stuttering moments. Something of value is that if I unplug one of the monitors, the choppiness becomes constant and doesn't go away until I plug two monitors in again. (fps stays perfectly maxed). CPU usage is low, temps are low (25-30 c) . All drivers for everything should be up to date.

Im really stuck cause I really don't understand what is causing it without any actual performance degrading . my monitors are both older and are 1600x900 (60hz).

ive also noticed that sometimes my mouse clicks don't even register during these stuttering moments. It does not seem like other applications or in general the monitor stutters, only within the game window.

any thoughts or insight would be awesome.. total longshot with such a niche game but Im totally out of ideas thank you!

 

[lowbudgetlobotomy]

I am probably just a moron but if it helps anyone in the future it seems the issue is related to the internal graphics. I believe the game is asking for too much cpu while the cpu is trying to allow the internal gpu to keep up is my hypothesis, I found a graphics card laying around that could accept both of my monitors directly and it seems to have solved all my screen stutter for the game. (to be honest I feel like I have a lot more cpu performance now too)

can be closed by a mod.