Weird trans issues when cold

When I first start driving my truck it slips going into 2nd gear and bangs hard into 3rd. It does this for maybe 2 miles or so and than works fine until it fully cools again. Its a recent rebuild with a manual valve body and type F fluid.

Is it a C6? If it is it's pretty common. It will be answered here.

Yes it is a c6. I am also having a problem with the B&M pro stick being hard to shift. So today i installed a brand new cable and it felt good. The second i started it to check the adjustment its hard as sh!t to shift. It is only hard to shift when running and its smooth as butter when the truck is off. Pretty much sucks

I was going to say it was the gov. sticking but it now sounds like something else in the vb is wrong.

Im going to drive it up to the place that built the trans and see what they think. It acts weird when cold still but it is shifting a bit easier.