Unless something has changed, I understand that the only source for clouds, even in METAR zones, is still Meteoblue as explained in a Dev Q&A from last year:
So even if the METAR says Overcast, if Meteoblue data are different, those are the ones that generate clouds in the sim. You should show the Meteoblue map at this location with the “Low Cloud” forecast to find out what the coverage should be. I am not saying that there is no issue, just to make sure to point to the correct data source when reporting an issue with clouds.