shifting issues on a new 2023 SR 2wd automatic

I have a pretty base model access cab 2023 SR 2WD with a 4 cylinder and 6 speed automatic trans. I bought it new about a month ago. It often has problems driving uphill. The trans often refuses to downshift unless the gas pedal is pushed down HARD to the floor. The ECT POWER mode usually resolves this, but driving up the same hills different days, the truck drives different every time. A couple of days back, I drove the freeway up a 5 mile grade twice the same day. In the AM, the truck drove great, kept 70 mph all the way, with me and the wife, no cargo. In the mid-afternoon, just me, no cargo, I tried turning on the cruise for the first time since I bought the truck. I did not actuate the ECT POWER mode. The trans started upshifting, then immediately downshifting again. This continued for the whole 5 mile grade. I shut off the cruise, then actuated the power button, stepped harder on the gas, but the gear hunting kept on. It probably cycled up and down about 60 to 75 times, and I could not figure out how to correct it. I did not think to try the manual shift mode. Has anyone else had this happen to them? It is at the dealer, and they said they could not duplicate the issue. hazzardley 1952