tool is broken on certain input

using this file:

https://github.com/tigrawap/slit/files/13802070/fail.txt

assuming the terminal window is smaller than the input text, the result is completely broken. for some reason the pager scrolls to line 6, instead of staying at the top. if you try to scroll up it wont. if you down arrow once, it scrolls up to line 2. then you can finally arrow up to line 1.