AS2023-Z value of hatch in advance drawings

[AntDrt]

Hello everyone, 

i'm facing to a little and frustating behavior with hatch & symbol in advance steel drawings.

when i explode to autocad my drawings, it appears there is a lot of Z values in my drawings

> for camera i understand the value is linked to the Z+ / Z- of the camera in the model see below:

and in the exploded drawing:

but in assembly drawings i got some Z but don't understand where it come from, see below:

Question; is it a normal behavior of AS ? or there is a bug in my drawing styles / symbols ?

does anyone facing this problem too ?

PS: i've checked my custom symbols and all of them got elevation in their source file.

thanks.