The relevant settings for visualization.
First click this icon:
The loot frame indicates the area that Knutschfisch needs to recognize whether it can be looted or not. That is what she does by
waiting for the bite within this frame. Minimize this frame as much as possible.
If there are too many bright spots within this frame, Knutschfisch will loot immediately. Also sets the sensitivity to 0. To find out the optimal settings for you, you have to play around with it a little.