Different renders of Terrain Splat Protypes in Real Time

I have made a little Terrain editor in game, but I have a question about Terrain SplatPrototypes:
When I change the AlphaMaps of a Splat texture on terrain with my inGmae editor I have a visible differents of color and opacity of Splat, respect the same change with unity editor.
I have used the same SplatPrototype and I have set the opacity at 1 in in-game editor and in unity editor but the difference is very visibile.

For change the AlphaMaps I have used this two line of code

alphaMaps[localZ, localX, CurrentTerrainDetailTexture] = CurrentTerrainDetailTextureOpacity;
SceneTerrain.terrainData.SetAlphamaps(0, 0, alphaMaps);

This is the differents between editor and in-game editor results



Anyone have an idea of this behaviour?

I have found a solution!
To have a look similar of the splat prototype like unity editor is necessary to change the opacity of all other Alphamps in this way:

var alphaMaps = SceneTerrain.terrainData.GetAlphamaps(0, 0, SceneTerrain.terrainData.alphamapWidth, SceneTerrain.terrainData.alphamapHeight);
alphaMaps[localZ, localX, CurrentTerrainDetailTexture] = CurrentTerrainDetailTextureOpacity;
//Set opacity value of all other splatPrototypes in the matrix to 0
for(int i = 0; i < alphaMaps.GetLength(2); i++)
      if(i != CurrentTerrainDetailTexture)
        alphaMaps[localZ, localX, i] = 0;

I hope that this trick can help someone.