Intermittent won’t start unless jumped. Dealer says battery and charging system are ok
So lets look at the starting system. Check cables at battery and clean them. Then clean the other end of these cables. When all cables are cleaned, then take your car to a parts store, I think they may be able to test your starter. If not you may have to remove the starter to have it tested. If it’s good we will look at the integrity of the cables.