Troubleshooting ideas? ESC Blinks (malfunction?), deceleration on highway

Yesterday my wife drove our 2020 Kona over Snoqualmie Pass on I90 on dry pavement, and repeatedly had this problem:

The ESC (Electronic Stability Control) indicator would blink and the vehicle would not respond to accelerator inputs while both on a straight-away going up a hill, and going around a curve (all curves are designed for 80mph driving), and instead slowed from about 65 to 45 in the fast lane which is dangerous because everyone else on I-90 is driving about 75-80.

The owners manual states:"When ESC is in operation, the ESC indicator light blinks" with second bullet point "When the ESC activates, the vehicle may not respond to the accelerator as it does under routine conditions."

There was no reason for the vehicle not to acclerate, nor for ESC to activate unless there is a bad sensor, and we want to figure out whether the car will continue to be highway worthy.

Thanks in advance and let me know what additional info I can supply or things to check.

 

@Wildeyed said "described in the repairs thread above"

Could you point out which page or provide a link? That thread is now 38 pages

 

I checked and adjusted tire pressures after reading that thread, because that could've caused ESC to engage (?). Before: 36, 37, 40, 43.

Now to test on some hills and curves