Fortunately, the sensor's auto-recalibration components allow the CO2 sensor to re-gain full accuracy after 2-3 weeks. In the meantime, you are likely to experience excessively high CO2 readings before it goes back down. Please be patient during this process.
The recalibration process might also occur during the first two weeks of the Pro/Node's first use.
If you have any questions regarding your sensor and its readings, please do not hesitate to contact AirVisual support.