Metahuman artifacts on Android app

When I export my Unreal Engine 5.6 and 5.7 metahuman project for Android I get these artifacts:

the problem is not the textures, because it happens also with a material with no textures:

Oh and this happens only on the OpenGL ES 3.2 backend, not with the Vulkan backand. Someone knows how to fix that? Or at least which is the cause?