4.10 gears 8th gear shift shifting

Have a 2019 JLUR 2.0 auto 8 and took a road trip to Savannah from Atlanta this week. I kept finding that as I would try to accelerate over 70 uphill, I would have to drop down to fourth before I can start gaining forward momentum. Couldn’t get to 80 uphill, only flat and downhill. I just lifted...

My Tundra with 4.10 gears and 35s would shift out of 6th way too often even in the flattest parts of southern OK and north TX. If you’ve got 37s (or even heavy 35s) with Rubicon 4.10 gears, have you been able to stay in 8th on the highway at 70+? This may be the last question I need to answer...