5R55E intermittent harsh shift
 

My 2011 4x2 Ranger will shift very harshly when shifting under hard-ish acceleration. If I drive it easy with slow easy acceleration, the shifts are smooth - it seams as though the more acceleration I use the harder the shift. Its mostly noticeable when shifting from 2nd to 3rd gear. I have no codes or indicator lights. This is a new vehicle to me and the previous owner said it has a new/updated valve body. I've searched this and other sites for where to start troubleshooting. So far I've found that it could be the adaptive learning and that clearing the tables may help but I am unclear on if this transmission uses that strategy. Other posts have mentioned band adjustments or new servos. Just looking for a place to start before I throw in the towel and pay a shop. Any guidance is much appreciated.