Did a clean flash 12.0.9 xiaomi.eu ROM on Poco X3 surya. Adaptive brightness is buggy: it decrease too low in the dark and doesn't remember my preferences. Or when I've set the necessary level of brightness in the dark ambient and left the phone for a few minutes, after unlocking the phone the brightness again in the lowest level and i need to increase it again. In the bright ambient adaptive brightness works good. Didn't have such issue on stock MIUI 12.0.9 ROM.