After a lot of trial and error I got my gas usage working in HA. The problem is that HA still gives a warning with the current setting (m³):
WARNING (Recorder) [homeassistant.components.sensor.recorder] The unit of sensor.hourly_gas (m³) does not match the unit of already compiled statistics (m3). Generation of long term statistics will be suppressed unless the unit changes back to m3
If I try to set it to m3 as suggested I get the following warning:
WARNING (Recorder) [homeassistant.components.sensor.recorder] sensor.hourly_gas has unknown unit m3
Any good solution for this or is this a bug?
Try going to Developer Tools | Statistics. You should be able to click on Fix Issue for your sensor.
This fixed my issue, thanks!