Hi, after testing out few things I found out that after you move the Music Box in any way, either using a vanilla piston or any mods (like Create, or Mekanism's Carboard Box). It won't work until you reinsert the music sheet inside it. You don't have to replace the instrument, just the music sheet. After that it starts working again, but it is a manual process.

Short video demonstration of bug: https://streamable.com/1n9nbb

I am using Valhelsia 3 1.16.5 modpack v3.1.8a

Thanks for the pull request. Additionaly, it did not work if it was pushed while powering to the side, that is also fixed now with b90e46e.