Forecast.Solar values are very low

I have setup the Forecast.Solar integration and when I look at the forecast values they are all showing 0. I have exported the configuration from HA and also checked the API call and think that I have used the same Swagger UI test case to view the same request directly against Forecast.Solar.

In Forecast Solar it shows 13685 kWH for tomorrow.
In HA the “Solar production forecast Estimated energy production - tomorrow” entity shows 0.01 kWH.

Data from the Forecast Solar Estimate API -


Extract of diagnostics output from HA

  "wh_days": {
    "2023-07-06T00:00:00": 12,
    "2023-07-07T00:00:00": 13,
    "2023-07-08T00:00:00": 11,
    "2023-07-09T00:00:00": 15

Is there a setting somewhere that I have wrong?