Shader Model 5 preview vs Mobile preview

Hi, I have huge differences between mobile and SM5 preview.
My material are simple texture connected to the base color node and the light is a stationnary point light. All settings are default settings. Here’s the results

SM5 preview :

Mobile preview:

What’s wrong please?

not a subject i’m familiar with but i’m not sure there’s anything wrong. mobile is going to have less complex calculations because the hardware isn’t as powerful. one would think that with lightmaps it would look the same but i don’t know what’s going on in the back end.

Lightmap has been built before both previews.
How can “less complex calculations” produce more light in the lightmap and inverted shadows on a mesh? I mean it’s a lightmap, a 2D image with shadows drawed on it. There’s shouldn’t be less calculations neither because lightmap are pre calculated, not dynamic and the lightmap resolution is the same.
I tryied to untick the “compress ligthmaps” option but there’s only less artefact but the problems (too bright + wrong shadows) are still here.