Screen not as smooth, tried changing lcd itself.

I added a video..

So this is a 2nd hand item. The screen cannot hold 2 press at the same time and it is not as smooth! its sticking. Tried changing the lcd with the same backplate and still the same! 3d touch is slow too! it’s like it has a default time for press. Should I change lcd or just go get a better model.

+will replace rear and front cam from an abandoned 6s

+yoobao battery or just go sell entirely

-touch id and double tap not working just home button

stressfull lol