The "CustomSpawnRules" NBT in spawners is misspelt as "CustomeSpawnRules"

 

See here an example of a spawner's nbt:

{MaxNearbyEntities: 6s, RequiredPlayerRange: 16s, SpawnCount: 4s, SpawnData: {CustomeSpawnRules:

{BlockLightLimit: 11}

, id: "minecraft:skeleton"}, MaxSpawnDelay: 800s, Delay: 20s, x: 230, y: 33, z: -36, id: "minecraft:mob_spawner", SpawnRange: 4s, MinSpawnDelay: 200s, SpawnPotentials: [{Entity: {CustomeSpawnRules:

{BlockLightLimit: 11}

, id: "minecraft:skeleton"}, Weight: 1}]}