Currently, Im working on a gateway for a player to fight Ice and Fire Dragons, and I want to set their age, color variation, and gender. This is done through nbt tags. However, when the gateway is active, the gateway is not applying those specific tags. Other tags though, like the NoAI tag, is being correctly applied.

What confuses me the most, is that when I summon the dragon with commands that has the exact same nbt, or put the nbt on a spawn egg, it works as intended.

This is how I have the entity and nbt data setup, which for some reason only applies the NoAI tag

This command summons the dragon, with the same nbt as the one in the gateway, and it works as intended:
/summon iceandfire:fire_dragon ~ ~ ~ {AgeTicks: 1200000, Gender: 1, Variant: 0, NoAI: 1}

You likely need to set finalize_spawn to false for the given wave entity. The dragon probably overrides those flags at spawn time.

I initially tried that, however it didnt work. i DID realize i put the finalize_spawn in the wrong location on the gateway, and its working now. so apologies if this was a waste of time. thank you though.