The geometry nodes modifier did not specify that it needs all custom data layers. Therefore the modifier evaluation code tagged some layers so that they will not be copied later on by calling `mesh_set_only_copy` in `mesh_calc_modifiers`.
The geometry nodes modifier did not specify that it needs all custom data layers. Therefore the modifier evaluation code tagged some layers so that they will not be copied later on by calling `mesh_set_only_copy` in `mesh_calc_modifiers`.