The affected version says 1.20.5 since there was no option for 1.21 Release Candidate 1

When applying a data pack to a world then uploading that world to a snapshot realm, the data pack stops working for some reason, I've uploaded a video of the issue happening at https://youtu.be/zpqMxTI0zzU and I've also attached a zipped file of the data pack I used below.

I'm still new to making data packs, this was my first one, so if I'm missing something please let me know.