Vertical position seems to be incorrect for a file

[Iey4iej3]

Sample PDF: https://www.math.ias.edu/~lurie/papers/HTT.pdf

If I run pdftocgen -v with the TOML file

level = 1
greedy = true
font.name = "CMBX10"
font.size = 9.962599754333496

I get a TOC with one line being

"1.1 FOUNDATIONS FOR HIGHER CATEGORY THEORY" 19 484.73089599609375

and if I use pdftocio to write the TOC into the PDF, and open the result PDF by PDF viewers (I tested zathura and okular), the vertical position seems to be incorrect.

pdf.tocgen v1.3.3
Python 3.11.2