White line around foliage for few starting seconds

When I play my project, starts a MainMenu map which loads a MainMenu Scene.
Whe weird thing is that loads it with some bad quality settings.

On the Start jpg you can see that “white line” simmilar to Stroke effect on Photoshop around the grass foliage.
After few seconds, about 10 seconds, that stroke effect dissapear.

What could be happening?
Thank you.