tranny shifting hard... until shut off

99 camaro 3.8- My transmission shifts slightly hard when it is cold, when it reaches operating temp. it drives and shifts fine. Then every now and again (every couple weeks or more) it really SLAMS when shifting. It does it through every gear. And its random too. Like today I was at a stop light then when I started going it did it. So it does it in mid-drive. But when I turn the car off and let it sit for only about 3 seconds and start it back up.... it drives just fine. Any thoughts on what?

tps sensor thinking its at full throttle? anyone think anything else?

is the trans fluid a good color? doesnt smell burnt?

tps sensor thinking its at full throttle? anyone think anything else?

is the trans fluid a good color? doesnt smell burnt?

Ya, it all checked out. And ive changed the fluid and filter only about 5000 miles ago.

any one else got any ideas? or agree with above?