I've recently been trying to add a Resource Pack which changes the music from the original minecraft discs, but while I was using this library and Merchant Markers. I'm not sure which one caused the compatibility issues with the Resource Pack so I'm gonna leave reports on both of these mods for you to investigate what caused the issues and if it was Merchant Markers instead.

I've spent hours making and changing the Resource Pack trying to find out what was wrong with it because I was doing everything right, until I tried it in a vanilla world, I found out it worked perfectly without the mods so I spent hours looking through my mods trying to find which mod was causing the issues and after a few tries I found out it was between Merchant Markers or Iceberg.

I also tried checking if it was because of me doing something wrong while making the Resource Pack by trying out a community made Resource Pack that changed the weather sounds (rain and thunder) and that also didn't work so I knew it wasn't because of me so it is because of the mod, it basically cancels any sound file that has changed with the resource pack.

This all happened in Java version, using forge (47.2.0) and the game version was 1.20.1.

Iceberg-1.20.1-forge-1.1.18
MerchantMarkers-1.20.1-forge-1.3.3