A friend of mine had weird starting issues like that with a new Hyundai Tucson. The dealer couldn't figure it out. He read something online and ended up getting a faraday cage - he keeps his smart key there when he's not using it and he stopped having problems.
ICE, HEV or PHEV version? Since it starts w/"remote" (phone app or button on the fob?), it sounds like its not a battery/charging issue? But if its a problem w/the button itself, how does it start w/jump? Sounds like a key fob issue, as dave suggests. (Bad fob battery? Not paired w/car?)
