KIA shift lock

I have a 2006 KIA Spectra automatic that shifts hard into 3rd gear sometimes. I had it serviced at 30,000 by a dealer and the problem went away. It’s now back at 50,000, but the dealer can’t tell me why it’s happening again. Anybody?

Time for another service. Usually at the 30g service they will change the fluid, the filter and the vacume valve. My guess is that they did not adj. the bands, and that is what it needs. Have the other things done at the same time, and have it done at a reliable independent service place, as long as it is one that wont void your warranty.

Do modern automatic transmissions still have bands?
I was under the impression that this technology went out quite a while ago.