Entities immune to fall damage are damaged when using minecraft:fall damage type in /damage

The bug

When using /damage, it is possible to damage entities that are immune to fall damage by using the minecraft:fall damage type.

For instance, the Iron Golem is immune to fall damage, and yet when running command

/damage @e[type=minecraft:iron_golem,limit=1,sort=nearest] 10 minecraft:fall 

the golem is still damaged.

I don't believe this is intended behavior, as similar behavior exists and the entity is not damaged. When running a command like

/damage @e[type=blaze,limit=1] 10 minecraft:in_fire

the Blaze is not damaged, and the error

Target is invulnerable to the given damage type 

is given.