Can't use Microsplat with biomes

If 2 Microsplat texture are used multiple time (for example the beach texture on 2 different biomes) the texture get black. I also have a problem that I can't find a way to texture the world is I use biomes for that reason.

In the screenshot below, I created 2 biomes, one in the desert and the other in a forest.
Both biomes work well when they are alone as the main graph, but break if I try to mix them in the same map.

To reproduce, try to use 2 times the same texture using Microsplat (I use "both" texture and splat)
Another way is to create 2 simple biomes and try to mix them together on the same map.

Not that due to another bug you have to match the number of textures in the graph with the Microsplat's number of texture.