When I try to charge or sync my iPad Pro (10.5”) on the USB port of my 2014 rMBP 15” dGPU, often the charge indicator in iOS will flicker on and off in 1 second intervols and will not allow syncing or consistent charging. What’s the issue? Should I do a Genius for this? RMBP battery has been relatively week and throughout its lifetime it has always been hotter than I would have liked...could there be some kind of defect? (The USB port problem is limited to the left-side USB port; the right side port functions fine; also, the problem occurs more often when trying to charge my iPad Pro than when trying to charge my iPhone 7, though it has happened with both) Anyone else have similar problems?