Polygon/reference disappear in survey (Grid)

Hello everything,

First, thanks to everyone working on MP, it’s awesome.

I imported a kml overlay on google map and since that, It’s impossible to create a grid survey over the kml shape, when I click on Survey (Grid), I see the world map!
The shape draw on google earth are 100% solid stroke and 20% transparent fill, 30m x 30m.
If I put a polygon point outside the shape, It’s ok, I can see all polygon point, but to make the grid right over the fly zone, I move the “external” point and the grid disappear. Impossible to see it again.
That’s weird.