SEN0642 UV Sensor - Reporting Bad UV Index

SEN0642: UV Sensor

Modbus communication is good, the sensor reports a UV Index of 15 for any Intensity reading above 3.6 (360 Raw)?

An Intensity of 2.5, reports UV Index of 10?

Any ideas why the Index is incorrect?

SEN0640: Irradiance Sensor

Modbus communication is good, but at ~1250 w/m2, comparing to my calibrated Fluke meter, the SEN0640 is ~200 w/m2 high?