Mouse lag for seemingly no reason?

I have tested this on 2 different computers which are the following:

Machine 1:
i5 4690k (stock)
gtx 1060
8gb 1600mhz ram
samsung 860 evo ssd (game is installed on this)
No razer related product or razer synapse

Machine 2:
i7 9700k @ 4.7 ghz
gtx 1080 ti
32gb 3200 mhz ram
samsung 970 evo pro (game is installed on this)
Razer synapse installed with a razer keyboard

On the first PC the issue is basically the same but basically happens everywhere, despite holding easily 60+ fps the mouse issues are happening in the exact same way and I was easily able to replicate them in Solar Array where it was the most extreme. On this same PC both CPU and GPU were capping out at 100% at all times, no temp issues though.

On the second PC there were no issues at all with either the mouse or the fps at any point. CPU was capping at 100% a lot more than my 8700k which is very funny but it didn't cause anything noticeable.

In conclusion this makes absolutely no sense at all. How can 3 machines which can hold 60+ fps see completely different results even when running at the same framerate? 1 of which runs at 60 but looks NOTHING like 60 fps half the time. Controller is somehow completely unaffected but the mouse becomes laggy and slow.