Why custom collision Object Channel behaves as WorldDynamic?

On my character I have OverlapTrigger - Sphere Collision component. I use it for object interaction and it is only needed for overlap events.

I use custom Object Type - Trigger, that has default response Ignore.

For the projectile I use custom Object Type - Projectile, that has default response Block. Here is settings:

For some reason the projectile will collide with the OverlapTrigger even though their settings are set to ignore each other. And when I set a setting on the projectile to Ignore the WorldDynamic Object Type the projectile will go through OverlapTrigger as expected.

Why OverlapTrigger is behaving like WorldDynamic even though it is set as a custom Object Type Trigger?