Xiaomi Light Sensor GZCGQ01LM works but the value is off

[mikephemera]

the Light Sensor GZCGQ01LM works with Gateway DMWG03LM Firmware 1.0.6_0016. It reports lux and update is all working.
But I notice that the value is off.
This is local value it reports from Xiaomi Gateway 3 Integration.

This is cloud value it reports from Xiaomi Miot Auto and Mi home app. This is accurate.

The shape is good so I downloaded the values and run regressions on both data. It's roughly a nature log curve. Not sure if it's a bug or just me. I tried to delete everything and add them back. It's the same. Technically it still could work with Template conversion.