Transmission Problem

I have a 1996 Chrysler Town & Country LXI with 142,000 miles. I had the transmission overhauled over a year ago, or approximately 10,000-12,000 miles ago. I was not real satisfied with the shop that did not work as I had to take it back several times before they got it fixed. The problem was that it would not down shift. Anyway, they finally fixed it and it has run fine until the past couple days.

More specifically, when I first run it in the morning I notice a little “bump” in the transmission and after that it will not down shift. However, if I turn the engine completely off and restart it, it works fine. And, I have not experienced a problem with it the remainder of the day. The problem only appears when I first run it in the morning.

Does anyone have an idea of what is going on, and if it is something I can fix? Or do I need to find another transmission shop?

Thanks,
Greg