2015 Camry with 4 cyl and Aisin 6 speed automatic

I just bought a new 2015 Camry last Sept and in the morning when it's cool I start the car and after 15 seconds I put it in "drive".  The transmission engages for a second, then it releases for about a second and then engages again.  It does this every morning and again in the afternoon when I back out of my parking space at work and put it in Drive, it cycles the same way.  At a traffic signal I was the first car at a left-turn signal and I put it in neutral, it's a loooong light and when the green arrow came on I was slow in getting going and the guy behind me honked (no, I was not on my phone) and when I felt the transmission engage I stepped on it...well...the transmission released from first gear, the engine revved way up and the tranny re-engaged and I smoked the tires.  Is this normal for this to happen with this car?  I took it in to have this checked and the dlrshp could not find anything wrong with it.  HELP!