Hesitation while accelerating 50-65 MPH?

Blew transmission seal was slipping a little bit prior to blowing seal sat for 7 months. Took in to repair they allegedly replaced seal, refurbished torque converter, and replaced some clutches. Gas tank was not emptied or stabilized during storage. Gas at half tank when picked up car would shift all gears and no issues intown once it got to highway speeds 50-55 MPH car would buckle a lot, the car felt like if it was bouncing up and down. Added half a tank of clean gas and seafoam treatment same symptoms if I fully gas it the bucking goes away with the passing gear once I lift off the passing gear it buckles twice and settles if I get it up to speed 65 MPH and cruise it will not buckle and maintain its speed.

obd2 readings
no codes
Mode$6b failed
EVAP failed
Long term fuel trim bank 1 0
Long term fuel trim bank 2 9.8
O2 sensors showing 99.2 efficiency.
MAF g/s on the dot of what it should be running and idling. Have driven 50 miles.