I have an F-150 that isn't shifting right. If it is under torque like accelerating or driving down the highway at interstate speeds it's fine. However, let's say I am in a city, driving around 35-50, and come up on a car. I let off the acceleration, coast, then when the car pulls away I give it a little more gas. In this particular situation it's like my truck can't decide to upshift or downshift or what, so it will buck back and forth. If I let off the gas or give it more gas it's fine, but it does not like moderate speed with a tiny amount of gas especially when coming off of a coast. Otherwise it's shifting fine. I put in a new filter and fluid recently, did not help. Any advice short of a full transmission rebuild is appreciated.