Mazda 6

I own a 2006 mazda 6 with automatic transmission. Sometimes when I am driving, usually when im going up a hill, and im on 5th gear. The car will jerk when I try and give the car more power, it will jerk from 4th to 5th. Either way I dont know what gear im on nor do I look because Im just tryna figure out if everythin is ok at that point.

The jerk is very noticable.

If you can help that would be best.

The technician at Mazda said the transmission was ok and he couldnt figure it out.