Transmission Issue

So back in December I left for deployment. I had to leave my jeep sitting until I returned in July. Upon returning my trans was slipping pretty bad. I set up and appointment at a local shop to get it checked out. The day that I went to take it in reverse was completely gone, and neutral had turned into drive. Horrible. I took it in and the guy explained that the torque converter had dry rotted and completely destroyed itself. Some money later, and the trans was back up and running perfectly.... Until today.

Story time. I am driving off base and pull up to a red light. Light turns green and I go to take off, but there was no taking off. The jeep revved up and barely crept forward. I instantly pull off into a parking lot. Put it back in park, then cycled through the gears. Tried to take off again and the same problem. I stop, drop it down into reverse, works fine. Put it in 1st, took off just fine. 2nd, just fine. Once I was up to around 20mph I shifted it into drive and it ran fine, until I stopped. Then it had the same problem. I'm no expert on transmissions, but I'm pretty dang sure I have a problem. Does anyone have any ideas on what might be going on? I luckly purchased an 18 month warranty on the transmission, but if it is a quick fix I can do I would rather go that route considering the shop had my jeep for about 10 days the last time. Pretty upset about it all.

Hope everyone is having a pleasant week.​