Baked light jagged shadows

Hi!

I'm trying out Unity for the first time. Just trying to setup a really simple low poly scene with an island. But I can't for my life get the shadows to render correctly when I'm trying to bake the light.

It renders correctly on some objects but not others, especially my island object (created in blender). I wonder if something is wrong with my uv maybe? I made a seam at the waist of the island so it is split into two round uv:s. Is that not an okay uv? If I increase the lightmap resolution by a lot it gets better but it is still jagged (and I get reeeally long render times for just these very simple objects, so it will be really hard to use those settings on a full scene).

I've tried to google this but havent found anything that works yet. I have seen that other people had trouble with jagged shadows before with the previous lightmapper "Enlighten" but I'm using "Progressive CPU".

Any ideas at all are very welcome.

The scene:
https://www.dropbox.com/s/0t1xi1jklajietm/Screenshot 2020-06-02 11.41.29.png?dl=0

The island UV:
https://www.dropbox.com/s/ok8pko52cm8nlgi/Screenshot 2020-06-02 11.42.11.png?dl=0

 

I now figured it out. I had just a very strong directional light to light the scene since my blender model was very dark. That was the cause of all problems. Using lighter textures and a lighter environment light worked a lot better.