For one of our products we are using the BME280 sensor. There are of these 2 sensors in each product. I noticed that in one of the systems, the sensors ambient pressure is much higher than for the other systems. On a single day, two systems indicate ~995 mbar (on both sensors). This seems to be correct since it matches with the weather data for our location. One system however has a pressure of ~1020 mbar on both sensors (in the same room). This deviation seems to be quite high and I don't understand where this could come from. Can someone explain what could cause such large deviations for a single systems ?
What's interesting is that BOTH sensors on this system deviate, so part-to-part variations seem unlikely, since then I would expect to also see this kind of deviations in and between other products.
There was BME280 HSMI document, you could check handling, soldering and mounting the BME280 to your PCB.