EditorGUILayout.LayerField do not get me correct layer I choose with it

Hello,

something I don't quite understand with the result of this command , so I may have missed something..

as a quick example I have a bunch of user layer added to the built in one of unity and for some of my tool i want to be able to pickup layer I want to use for some interaction in my game using this LayerField things using LayerMask layer; variable like...

ok well this is working fine if I am using that in a simple inspector when i expose the variable, I get all my later listed and pick the one i want... But when i do same things within a custom inspector or EditorWindow using this EditorGUILayout.LayerField, I also get my layer listed as I expect but choosing one of my user layer will get me some built in layer chosen instead ( when I check that in Debug view ).

I am using C# by the way

So do I have to do something more than now to get back a proper selected layer using Editor command ?

thanks in advance to clear me up on this..