Some sort of lag/bug i don't know!

Some games when im playing and im about to scope someone the scope of the weopen is not working or is switchiong on and off like on the video i will add in the end! I'm not sure if it is a hardware issue?

Video -> 

https://drive.google.com/file/d/1cPKOCav05wOACVDtoOCI4la1wd1zP-tg/view?usp=sharing