Be sure you take some video of what your doing. Then you can figure out what was going on.
If you chuck it without power, pick a day with 5 to 10 mph wind. That way, make the first throw (have a little up elevon) about a foot off the ground into the wind. If it nose down immediately, move aft. If it rides high and tends to go nose up, CG needs to be forward.
That way , 3 or 4 ft high chuck will not cause damage.
Also, roll is going to be quick, so be prepared.