In short, whenever I am playing a game on my 144hz monitor and I open an application my 60hz monitor that has some sort of video (some that I have used are YouTube in Chrome, Twitch app & in Chrome, and Discord only when using webcams), it causes my game on my 144hz monitor to seemingly drop frames/become laggy.
After looking it up, I finally was able to deduce that this is a common problem for people with two monitors that have different refresh rates. This supposedly happened because of a Windows update back in 2015 or so that causes the refresh rate to sync across monitors and the only way to truly fix it was to turn off the Aero setting but only if you have Windows 7 as it is not possible in Windows 10. I have seen many suggestions of how to fix this issue but none of which have worked for me. I didn't see too many recent posts that were answered so I thought I would bring this up in here to see if anyone has a fix for this???
P.S. I have turned hardware acceleration off in every program and it doesn't work. I also do not have an igpu.
Gigabyte AORUS FI27q - 144hz (DisplayPort)
Acer KG281k - 60hz (HDMI)
CPU: AMD Ryzen 7 3700x
GPU: AMD Radeon 5700xt
Edit: this problem only occurs when playing in borderless/windowed full screen. If I put it in full screen it seems to fix itself. Although alt+tabbing our of fullscreen is annoying.