As stated above, when you have “Improved Input Response” feature turned “On” and you go to “Play Menu”, when you go back to the “Main Menu”, it creates streaks of gray lines across the screen. Albeit they disappear immediately after, but it is still annoying and shouldn’t be there in the first place.
Attached within this report are the with and without the feature being on.
This issue is being tracked at MCPE-188337.