According to BMP280 datasheet, the marking with "2UG KS" is the right part for BMP280, while the marking with "009 KM" is not the right part for BMP280.
This is because we never had BMP280 parts with marking "xxx KL" and "xxx KM" before. May I know where you purchased these BMP280 parts?
Interesting. If I read the datasheet I thought that KM would be acceptable; "(L = "S", "M" for new variant, both part number 0273300436)".
Some are bought by our EMS, some where bought from win-source.net. (Well aware its not an authorized distributor) It has been difficult to procure the component, so we have at times been forced to buy from spot markets and other alternative sources.
I appreciate your responses.
Sorry for my mistake.
According to the new version BMP280 datasheet at https://www.bosch-sensortec.com/media/boschsensortec/downloads/datasheets/bst-bmp280-ds001.pdf, it is true that BMP280 with marking "009 KM" is the right part because "(L = "S", "M" for new variant, both part number 0273300436)". I was reading the old version of BMP280 datasheet as shown in the attached file.
Therefore, both "009 KM" and "2UG KS" markings are right BMP280 parts. Sorry about that.