Transparent Object exclude from ExponentialHeightFog if AtmosphericFog is activated

Hi,

This is rather complicated issue and maybe you happen to know it.
There are sea fans under the sea. The sea water color is implement by using ExponentialHeightFog.
They are fine until I add a AtmosphericFog, the transparent sea fans become not affect by ExponentialHeightFog.
Why?

Before:

After AtmosphericFog: