Hello Z friends.

I've recently started having this issue where my Automatic (should have gotten a manual I know) '07 (120k miles) would not shift gears in both Drive and Manual mode. I've noticed whenever I try to place it in manual mode after a few seconds of driving the gear indicator switches to drive and seems like its not switching gears in drive cause rpms will just keep going up and the speed stays the same this mostly happens after a cold start. The transmission fluid was changed about 5k miles ago due to a hose popping off and everything has been fine until recently. there was a time a while back where It would not go into 5th gear on the freeway and suddenly the gear indicator turned off and CEL,ABS,SLIP came on pulled over and there was smoke coming from under the car it was fine after letting it sit. Checked the code it came out as U1000 but everything was fine again and hasn't happened since. Are these normal issues for the A/T?

Any help on this is greatly appreciated and I apologize in advance since I'm a beginner when it comes to cars.