The outside unit fan will stop running and then the motor will start making humming sound and after a while of that it will start to make a kind of hissing sound, sometimes I catch it and just shut off the outside unit from the electrical panel for a bit then I start it up again from the panel and the fan will start outside and then everything is fine for a while till this happens again, and it only seems to happen during the hottest parts of the day, at night or in the morning when it first kicks on everything is OK working normally.

Check or replace the run capacitor for the fan outside OR the fan motor itself might be failing.