Custom Biomes are not useable in Predicates

When using a datapack with custom biomes, adding one or more of those biomes to a location predicate will cause the predicate to be unusable. It also prints an error ("Couldn't parse loot table ultimate_survival:biome/mystical_reef") into the log when doing so, but it's not fatal. Also, yes, the predicate is located in the namespace's predicates folder.