Hello folks happy blessed morning from this side, I've been working on this machine (D6R) I rebuild the transmission not long ago, service the transncooler as well as the engine cooler but the problem still persisted. Hopefully waiting for your intake on this,thanks to you y'all.
Did you rebuild the torque converter and transmission pump?
Cross checked the torque convertor for any wear or tear as well as install new transmission pump but to no avail the problem still persisted.