help fixing a datapack (not mine)

There's a datapack I really love using, I pretty much never play without it. However, it only goes to 1.20.6, so I modified it to work on 1.21, but it's still having some errors. I can try my best to explain it and everything, but if someone is more familiar with From The Fog from Lunareclipsestudios that'd be helpful. I can only get a couple of sightings functions to work, and when they do it's only manuually, they won't happen naturally. I'm not sure why, as the code is very similair though. And yes, I've changed all the folders such as "predicates" or "functions" to "predicate" and "function" and changed the pack.mcmeta to the correct number, I've seen a lot of stuff and none of it is really helping. I can send the original pack as well as the modified if you need.