The recoil works strangely

I have added this at the end of the “Fire” event in the FPS Blueprint example:

And it seems to be working okay… almost. When I shoot I get pushed back, but not when I shoot downwards — I do not leave the ground (but I do get pushed in plane, yes). But when I jump and shoot under my feet I do get thrown upwards. What’s the difference and how should I change my code to be able to use my gun as a freaking rocket engine?