Trailer stability while parked

Had the same problem when I went to the longer 35 ft trailer. You need to determine if the movement is front to back, the X Chocks will help with that, or up and down, the X Chocks will do nothing for that. A scissor jack under the axle works wonders. I chased this problem for some time and tried an old scissor jack I had in the garage and that got rid of most of the movement. I'd try that first or even experiment with a bottle jack if you have one on hand. Don't put too much pressure on the axle, it doesn't take much.