Correct no "P" code id seen so it's hard to diagnose.
The over temp issue was caused when the shift didn't happen between the 3rd and 4th then between 4th and 5th gears in normal driving after the trans is at operating temp. Other wise it remains at the correct temp until it stops shifting normally and revs to 4500 before manually forcing it to shift to the next higher gear. It will shift itself back down to 3rd or 4th if the rpm's fall below the 4500. That would cause any transmission to operate in higher than norm temp I believe.