2000 Chrysler LHS Limp mode

I have a very random issue with the transmission. Sometimes it is stuck in second gear with all the PRND21 lights lit up with no Tachometer and then sometimes, it will drive fine, and then when I slow down to 20MPH it will get stuck in 2nd gear but only the D light is on and I will have the tachometer and I will have to shut of the car and restart and then it is fine for a little while until it happens again. I have changed the input and output sensors as well as the solonoid pack inside the transmission and just the other day I replaced the Transmission Control Module, but no fix. Is there any way that there was crap that got into the valve body and is causing all this, or would there be another reason? I am so confused as to what this could be! Note: when I changed the solonoid pack I had to split the valve body, but I am very sure I got it put back together right because sometimes it drives completely fine. Any thoughts? I brought to a transmission shop to let them work on it and they couldn't figure it out.