What is up with my character?

Do our characters have a mind of its own or something? I just don't get it cause, how can i run my line so well.... and then all of a sudden my character bugs out as soon as i ollie off a ramp. i instantly ragdoll out of nowhere. Its really annoying. It happens more than my actual skating. Its like you have to land on the ramp on a specific spot and jump off a ramp in a certain way without making my character fly all over the place. Tell me how that makes sense. Cause it doesn't to me. Almost like our characters have no brain at all...... Fix it.