Problem with new ATS trans

[ARARAR]

Does anyone think they may know what's going on? I just had a new ATS stage 1 trans installed a few months ago of months ago and all seemed well. At first it did shift a little harsh but seemed to smooth out nicely the first week. After about 1k mi. when I would first start it up in the morning and wait for all my gauges to kick in and put it in gear, reverse or drive it would want to surge like it was under a load or like I put my foot in it and it and blow black smoke. I would have to depress the brake and was lucky my emergency brake was still on. As soon as I would start out it would settle down and drive great and I could go down the street just fine. I could even stop and restart my engine and it wouldn't do it again all day. This would only happen first thing in the morning after it sat over night. Right now I'm going round with the local authorized shop with what the fix may be.. They have replaced the triple loc torque converter, that didn't solve the problem and are now in the process of replacing some solenoid in the trans. I have 185k on my truck and previously had a BD torque converter and valve body in the stock trans. and was noticing it was getting a little tired after about 150k and decided to up grade with a totally new rebuilt trans.