Bambu studio bug?

I would like to create a name tag. For this I have created a 0.2mm thick text in the first layer of a body. After that I colored the text in Bambu Studio and assigned it to another filament. The result in the slicer is strange.
Here are the first 4 layers that the slicer creates:

Layer 1:
grafik

Layer 2:
grafik

Layer 3:
grafik

Layer 4:
grafik

The first layer is OK.
In the 2nd layer, the first layer is overprinted black.
The 3rd layer is white again.

What is the slicer doing there?

Did you ever figure this out? I am seeing the same thing.