That bump.. means you did it right
When flying, you’re not supposed to follow another plane too closely. Not just due to the laws of man, but also the laws of physics. They leave behind wake turbulance, which is a disturbance in the air generated by the wings of the plane pretty much any time the plane is off the ground. The slower, heavier, and cleaner the plane is flying, the more disturbance it is leaving behind.
This weekend we did 360 turns, at a tight 45 degree angle. Those can be fun - you basically feel the effects of a couple G’s. As it turns out, if you do a 360 turn, at 45 degrees, and you do it correctly - you run into your own turbulance, and get a nice bump confirmation.