I’m experiencing the same issue with disabling the temperature and humidity sensors as you are.
In the Aqara app, the functions are switched off, and no values are displayed.
However, the values are still shown in HomeKit.
The sensor is connected to my M3 via Zigbee, and all my Aqara devices are exported via HomeKit integration.
Personally, I wasn’t impressed with the Matter integration
Never change a running system
Here you can see the isuee:
Aqara FP 300 First Review (Pics&Vid) - Aqara Products - Aqara Forum