With the standard electric front jacks and rear stabilizers on a 2009 BH3670, you will get some bounce. One technique for setting up is to find level for the trailer front to back with the front jacks, then lower the front about 3/4". Then drop the rear stabilizers snug and raise the front back to level. Placing screw or scissor jacks just in front of the tires under the frame also helps.
Consider adding Ultra-Fab stabilizers, or JT StrongArms, or a similar bracing system to further reduce the movement. So long as the center of the rig still has most of its weight on the tires/suspension, there will be movement. Replacing the original front electric jacks with something like the 4-jack Reico-Titan Ground Control system will also give you more stability. I prefer the Ground Control because it's electric, each jack is independent, and you can install it yourself.