Modified earth mask in nesting

Hello everybody.
I am working on a hydrodynamic simulation at the mouth of a river, for this I use 3 nested domains. In each one I edit the land mask, with the following result.

The simulation succeeds by activating.

define AGRIF

define AGRIF_2WAY

However, when reviewing the outputs of child 1 ( we notice an affectation in the ground mask (mainly in child 1).

How can this behavior be avoided?
Why does this phenomenon occur?

Thank you in advance.