Fluid makes stripes on transparent obstacle

Hi,

when I simulate fluid hitting a transparent plane, that is rotated some degrees for slow slipping downwards, the fluid shows up stripes, especially on the bottom side. I attached two stills …



I tried to rise the resolution, subdivided and smoothed the plane, made the plan thick enough - but the stripes won’t disappear.

Do you have any suggestions? I’m learning Blender for a few weeks now, so please apologize my noob question!