4l60e 1-2 2-3 sliding in
 

I'm new to ls1 so bear with me.
Today i noticed the tranny is sliding into gear very slowly (1-2@2-3).
I just bought car 1 month ago and tranny was rebuilt right before i got it.
It seemed fine for a couple of weeks now this.
The converter is 3600 tci ssf w/ about 30,000 miles on it. It also jumps out of lock up sometimes for no reason.
Any help would be apreciated.