I did some investigation, it seems to be caused by the scroll bar position not being reset after searching. If you scroll down, then search something that has a list shorter than where you scrolled to, the scroll bar will be out of bounds since it is not reset to the top.
The window resizing glitch is unrelated- hope this helps!
Edit: The scroll bar will return to the bounds when you scroll once.
Can confirm for 21w11a:
Seed: -4533527507201964851
Coordinates: -84 9 -927
Not fixed - see below
seed: -2526789703873195176
coordinates: 12 30 -35
Can confirm for 21w11a.
Can confirm for 21w11a.
Cannot reproduce; tried in both 1.16.5 and 21w11a
Cannot reproduce, they worked for me
Fixed in 21w11a.
Can confirm. Coincides with chunk borders.
Duplicate of MC-219948.
Can confirm.
Can confirm for 21w11a.
Can confirm for 21w10a.
Can confirm for 1.16.5 as well as 20w10a
Can confirm for 1.16.5
Sorry for not clarifying, this bug occurs in the singleplayer worlds list and does not involve window resizing.
Can confirm in 1.19.2