BUG in planar flipping optimization flag

[XuliaDS]

Hello !
I think there is a bug in the planar fliping optimization filter when marking the flag: updated selection. I have created an example below.

Original mesh:

Planar flipping optimization + updated selection:

Planar flipping optimization without updated selection:

I am not sure what it is considering as selected. As you can see, with the updated selection flag ON, vertices that are not selected are also being moved.

I am using version: MeshLab2023.12

Any thoughts ? Cheers