The voltage drops to 1.6V when the signal is expected to remain at 3.26V?
Apologies - there is a level shifter from 1.8V to 3.3V on this pin on the Dev Kit carrier board. So the E_IO_HV for this pin should be cleared/0. You can see the schematics here, in P3737_A05_Concept_schematics.pdf: Jetson AGX Orin Series Developer Kit Carrier Board Design Files
To double check that the right pin is being configured, where are you accessing this pin? Is it pin 22 of the 40-pin expansion header?