2005,My car will not start Intermittently. I purchased a new battery 2 weeks ago and yesterday the car wouldn’t start. Got a jump and

My car will not start Intermittently. I purchased a new battery 2 weeks ago and yesterday the car wouldn't start. Got a jump and the car started just fine, tested both the battery and the alternator and they both passed. Started the next day 2 times, and then wouldn't start the 3rd time after driving for about 45 mins. Got a jump and the car started fine again. Drove about 15 mins and the car started fine, removed the negative battery connector and the car did not die. What could possibly be the issue?

Thanks!

My car has 185000 miles.
My car has an automatic transmission.