Illusioners have a using spell animation wich is used for celebrating for every other illagers exept ravagers, but illusioners don't use it. They will only jump up.

How to reproduce:

1. Start a raid using "/effect give @s minecraft:bad_omen 100 0 true" next to a villager with a job. Build walls around the villager to not make raiders attack him.
2. Wait for the first wave to start and spawn an illusioner using "/summon minecraft:illusioner".
3. Make sure the illusioner has joined the raid. He joined the raid if he keep walking around the place where the villager is without stopping.
4. Kill the villager (not with /kill) and look at the illusioner.