Never had a Nothing Phone before, but have had varying degrees of similar issues with other phones over the last 10 years.
As most do, I also purchased a screen protector with my NP2a. Cleaned the screen and applied as I have with many many others. I immediately faced poor screen responsiveness. I have persevered for several days and nothing I do, settings wise fixed the issue.
I say fixed the issue as I have. It’s the screen protector in my case. It was a Spigen screen protector. The same make I have used for the best part of 10 years or so.
The other times I faced similar issues was due to cheap screen protectors, not ones from Spigen.
I removed this Spigen SP before typing this and felt compelled to write a post here.
My issues have completely gone. The screen is very responsive.
I may look at the Nothing Phone screen Protector, or a cheap alternative to see what suits.