BME280 multiple jumps in temperature below zero degrees

[rats]

My BME280 shows strange jumps in temperature if temperature goes below 0° C

[Jet]

Hi Sir:

   There are some questions to confirm with you.

    How many BME280 sensors did you test?

    Do you have a reference device to confirm the test temperature change?

    In normal ambient temperature, could BME280 get the correct values?

     Looking forward to your further information.

[rats]

I only have one BME280. As you can see in the chart, I have an additional SCD30 as a second sensor an I have an additional thermometer to verify the temperatures. If the temperature is above 0° C there are no temperature jumps as shown in the chart.

[Jet]

Hi Sir:

       Please see the following picture, which was from datasheet of BME280:

      

       And BME280 temperature full accuracy range is 0--65° C.

[rats]

The official product flyer says: full accuracy between: -40 ... +85 °C:

Full accuracy aside, I would at least expect the sensor to function properly in the specified range. And below zero it does definitely not.