HDR doesn't work on Steam Deck OLED

[ultimate-deej]

My setup: Steam Deck OLED, HITMAN 3 installed from EGS via Junk-Store. Without the ZHMModSDK HDR appears to work, I can also see the HDR badge in the quick access menu. As soon as I install ZHMModSDK all the colors start looking way less vibrant as if contrast and/or saturation are turned down, and the HDR badge is missing. Mods are all disabled.