After moving, my mouse frame-rate is way slower on my main monitor, but normal on my second one. What could be causing this?

I just moved two states away today. When I set up my pc and monitors and tried it out, the mouse moves at noticeably very slow frame rate, but only on my main monitor. When I move my mouse to my left monitor, it moves completely fine.

I got no clue. Everything was running perfectly two days ago when I took it apart.

My main monitor is a 32-inch LG UHD 4K monitor. (Link to the Amazon listing I bought it from: https://www.amazon.com/dp/B08ZJPV7FJ?ref=cm_sw_r_cso_cp_apin_dp_688P1FJJG11SCKSB64AR_3&ref_=cm_sw_r_cso_cp_apin_dp_688P1FJJG11SCKSB64AR_3&social_share=cm_sw_r_cso_cp_apin_dp_688P1FJJG11SCKSB64AR_3&titleSource=true&csmig=1 ). My second monitor is a crappy 1080p HP S2031. I tried lowering the resolution on my 4K monitor, but that didn’t change anything. Like, I can still watch 4K movies and they look great, but when I move my mouse over the image, the mouse is still skipping, without affecting the movie at all.

I’m not great with computer maintenance. I know how to dust it with compressed air, but anything more requires very specific instructions. Just saying, if you ask me for a detail about my pc, you’ll have to tell me how to find it, unless it’s just system > about.

My pc specs are:

Intel(R) Core (TM) i7-7700K CPU @ 4.20 Ghz

16 GB RAM, graphics card is NVIDIA Geforce GTX 1080 (8 gb), 64-bit processor.

Any help is appreciate! Please…