Stabilizing jacks don't really stabilize much at all

Some electric stabilizers are ganged meaning one switch lowers both rear stabilizers at the same time. If you have these it is critical that they are block sufficiently so that both stabilizers hit your blocks at the same time. If not you may only have ground pressure on one stabilizer. I used to lower the rear stabilizers with the tongue a little low. Then use the tongue jack to bring to level and load the rear stabilizers more. Then firm up the front stabilizers and then firm up the tongue jack a bit.