eleven250

hi i have an issue with my is250 2011 transmission
It seems theres a small delay when downshifting 4 to 3
sometimes its just a small delay and sometimes its hard downshifting feels like a small kick
it kicks just when i give it a command
sometimes with ect power it kicks by itself too

if give it a command with gas pressed no delay no kick everything is normal..

So i read online something about disconnecting the battery for an hour and then go for 20 minutes drive

Well it did resets the ecu the car felt a bit different but issue still exists

What could be the issue..? I thought of ordering ecu off ebay

could it be a ECU?

Oil and filter was replaced at 77k miles im now at 92k