Recently bought a used 2016 Titanium. The liftgate usually opens in all the typical ways, double click the remote, inside button, foot swipe if I do it right. On occasion, maybe 75% of the time, it won't close with any of the aforementioned. Rarely however does the upper button on the tailgate itself close it. I've searched here and done the recommended 'reset' (disconnect the battery, wait 20 seconds) with no results. Any ideas?