Question 1440p (Wide) lower fps?

[ign]

Currently I'm playing csgo and i'm wondering does 2560x1440p Wide (WQHD) monitor lower fps compared to 1920x1080p (Normal not wide) even though I'm playing the game on 1024x768 resolution?
pc specs
rtx 2070 super
i7 7800x
32gb 3000mhz dual
I'm just feeling that I'm loosin fps bcus of this monitor but idk I'm newbie at this stuff

 

[Nemesia]

Same performance. 1024x768 is 1024x768 on any monitor.

Why are you playing in 1024x768 with a RTX 2070?