I had this issue where I would plug my PS4 controller into the USB slot on the PS4. I would not get a yellow light bar signaling that it was charging. I have a PS4 charging Stand Connected to my PS4 as well that runs just fine in that USB slot so I know it's not the USB port itself. I tried 2 controllers neither of which worked. However I was able to fix it simply by shutting my console completely off. Not in rest mode but all the way off. I let it sit for 5 minutes and when I turned it back on my controllers were charging once again. I hope this helps you out.