If you make multiple sounds in sounds.json point to one audio file, only the first definition works, and the rest are ignored:
{
"ambient.cave.cave": {
"category": "ambient", "subtitle": "Test",
"sounds": ["test"]
},
"ambient.weather.rain": {
"category": "weather", "subtitle": "Test 2",
"sounds": ["test"]
}
}
If you try using /playsound on ambient.cave.cave, it works fine, however ambient.weather.rain has no changes.
Cannot reproduce with the sounds.json provided; both play the sound as normal.