LUX is unlikely to be accurate in our environments.
Lux is a measurement, but in most cases around the home, it's an approximation. Maybe you have a Sensor that has a Lux value and maybe the manufacturer tossed in some calibration at the design step. Individual devices are going to vary.
You go buy a bulb and it displays a Lux value, perhaps. For any specific bulb, it will be a reasonable approximation, but there on the side of the bulb is "dimmable" and now Lux is useless. No two bulb manufacturers dim the same.
Lux is NOT a measurement for Outdoor (sunlight) either. Extrapolations have been made, estimations exist, authoritative sounding numbers are on the Internet.
It's not that the approximations are bad, it's just you can't rely on them to be the same, room to room, house to house, etc. without using a calibrated meter.
Know that Lux as produced by wx-ApiXU-Driver and Luxurient-Driver are calculated values. Not even a hint of reality to them. An equation, that assumes a full sun, outdoor, cloudless noon day, is 10,000 lux. Dead of night = 5 lux. If you know the time of day and hoe much cloud cover there is, a value for lux can be interpolated.