Model Name: ROG Phone 5 Firmware Version: ww_18.0840.2201.226 Rooted or not: Not Frequency of Occurrence: Always APP Name & APP Version (If your issue relates to the app): All apps After latest update that had "Optimized audio parameters", headphone audio via 3.5mm jack seems broken. Any app that that tries to play sound has loud hissing first few seconds the audio starts playing, as well as the audio sounding absolutely distorted and like an overdriven amplifier that's clipping. This only happens when tested with my daily earbuds Soundmagic e10, which have ~50ohm impedance. When tested with high impedance Sennheiser 650 which are 300 ohm the distortions disappear. So it seems the impedance detection for the audio jack might be broken.
The audio seems to have fixed itself after I plugged in the beefy headphone. The issue likely is something with the software calibration procedure, as plugging in the high impedance headphone fixed the amplification for the low impedance one.