Remove "merge" layer

I’m trying to print a sign in two colors (base in black, letters and logo in white)
I have a K1 Max and I’m using Creality Print.
I came across the following situation:
Until Layer 5 I am making a “smooth” base and from Layer 6 I change the filament to print the writing and logo.
However, in Layer 5, the slicer creates this “merge” between the base and the writing… in addition to taking much longer to print this Layer due to the details, the bottom side is full of “defects” as it is not a fluid print. .
Doubt! Is there a way to eliminate this “merge” that it does? Leave layer 5 smooth and start writing on layer 6?

Have you tried increasing the resolution to 0.10?