Actor jittering or looking in the opposite direction while following cursor

Hey there,

I’m trying to make my actor look at my cursor.
This is my blueprint:

But for some weird reason, the actor jitters weirdly whenever I’m directly above or below it:

There is an invisible plane on the actor that is used for the tracing of the cursor position, but just hidden.

When I remove the Z-pin it just points exactly at the wrong direction:

I’m realy stumped on what is happening here.