I am seeing the same thing with this sensor - 0.3 and 0.5 show values, but 1.0 and 2.5 are always zero. Occasionally there will be a small value on PM10 but it returns to zero on the following reading.

I published it myself as phzi/DFRobot_MultiGasSensor@2.0.0

Whoever owns the dfrobot account on platformio could just run this command:

pio pkg publish --owner "dfrobot" --type "library" DFRobot_MultiGasSensor-main.zip

(see https://docs.platformio.org/en/stable/core/userguide/pkg/cmd_publish.html#id1)

It would be great if DFRobot stayed on top of adding new packages to the registry