Hi, I am having the exact issue linked below but I can't seem to figure out how to fix it on my minehut server. https://www.spigotmc.org/threads/experience-orbs-merging.359246/
yes, all files were uploaded manually but not one at a time, if multiple files were in a folder I uploaded them all together rather than one at a time.
I have added the datapack "more mob heads" to my server and reuploaded multiple times and followed all tutorials but I can't get it to work, it is says it's enabled but it is not working for any players.