Question about using sensors?

Hello! I have a quick question about whether this is normal behavior. I use 6485 151kv skyartpower motors with a Spintend ubox v2. When having sensors plugged in I notice on the bench when I apply brake super fast and hard after spinning the motors forward the motors sometimes like to go suddenly spin backwards for a second. Is this normal behavior of sensors?

How do you have your VESC set? Current, smart reverse, etc?

90a/-55a motor no smart reverse. Using Spintend uni1 v2.