Not shifting automatically into third and up, only upstarts if I use the manual shift

Hello, I have a 5 series 528i e39 triptronic. My car has been hesitating to shift through gears, but they do shift smoothly only first and second gears are fine when done automatically, but soon it would have some trouble changing on gear three with high revs, if I push it manually it would change gears with no problem. About three weeks ago the cog light came on for the transmission so I changed the transmission oil. But still no difference, but since then I have smelt a strong burning smell every time I come to a slow stop. I have had a diagnostic and they said there are no codes on the transmission. I have had the ABS replaced but for some reason the lights are still showing, with the traction control symbol. I have replaced two new wheel bearings, but I am convinced one of the wheel bearings have broken on the passenger side. I have replaced the water pump and thermostat. Please do you have a idea what is the cause? I hope it is not the transmission itself or the solenoid. Thanks