So I was playing survival and i noticed i was getting frame drops while walking in a certain part of my base which happened to be my stairs to my door, at first i thought it was my pc acting up but then i realized it wasnt specific to that one point in my base/house thing.

When i hit F3+G i noticed it was while crossing into a specific chunk and only from a certain face of the chunk. this happened while entering 4-5 chunks in a horizontal line in my base and started getting very annoying as i started playing more as the frame drops weren't like normal frame drops and it would make my game freeze for half a second. dropping from 100 fps to an estimated 1-6 fps for half a second, but it only displays as a 70 fps on my RTSS fps graph and counter

As i started messing around with it more i realized there were minor frame drops which were hard to notice everytime i crossed over from one chunk to another but the noticeable ones were in that long stretch of 4-5 chunks of which 2-3 happened to be where i made my base. 
I dont know if its just this particular world because this is the only world i made on 1.17 to play survival with shaders on.

(note: its not anything to do with the shaders because those same frame drops do exist with shaders off and with tweaked video settings with it dropping from 300+ fps to 1-10 fps for half a second on those same chunks)

It seems to be very random but consistent with every new chunk you step into giving you frame drops of different intensities depending on the chunk. my best guess is that this is either probably something to do with the way each chunk is updated as you enter into them. but idk thats just a guess. Ive seen some similar bug reports as well so im assuming its not just something related to my PC but i guess ill update this more once i gather more information about it and test it on other versions perhaps if I dont zone out and forget.

(for some reason it doesnt let me select 1.17 as a version so i had to chose 1.17.1)

(this isnt to complain or cry about the bug or to beg the mojang team to fix this, i just like doing stuff like this)