This may sound silly, and I am NOT a mechanic, nor claim to know a lot about cars...
But, perhaps check your catalytic converter?
I know, given the advice above, seems from left field, but,
I have 2015 Exp XLT with just under 70k. I had bouts where the engine would sputter, misfire and lose all power after hard acceleration. In the worse instances I would need to pull over and pause and restart and it would "seem" fine. Eventually, on a rainy night recently, I accelerated hard and the engine blew. My mechanic was at a loss as all seemed otherwise okay (prior to the incident).
Shortly after getting the engine replacement, I stopped in for a requested "follow-up look-around" and he pointed out another Exp, 2016 in the shop, ALSO for a engine replacement!
He noted on that one though, the catalytic converter was clogged. He asked if I had experienced any of the symptoms I noted above, and then noted that if I had brought it in I could have possibly avoided a needed engine replacement...
Your noted misfire issue reminded me of one of those symptoms, and with no other obvious cause, can't hurt to at least look...
Best of luck, I hope it helps, if not you, somebody else!
japii