BME280 and BME680 humidity accuracy

Hello,

I have a design where I can plug either BME280 or BME680. I am using BME280 driver version 3.4.2 and BSEC driver (full one not lite) version 3.5.10 for BME680 driver and version 1.4.7.4 for BSEC. Software is running on ESP8266. I am using float calculation for both.

I am seeing differences in humidity measured by BME280 and BME680 (and temperature also)

I have tested different devices and here what I see:

Same board, same place, same time, just replaced the sensor:

Two different boards, same place, same time:

Could it be that the humidity offset is linked to the temperature offset? And if not what could be the cause of this offset

Normally I am adding an offset to temperature after measurement so that sensors indicate right and same temperature. But I just realize that there is an offset between these 2 type of devices for temperature.

Pressure measurement are almost identical between type of devices.

I have also tried integer calculation (both 32b and 64b)  on BME280 but the measurements where the same as when using float.

Any idea where I could look for?

Thanks.

NB: I don't have a reference for humidity so I don't know which sensor is right, even I would think that BME680 is closer to real value.