[BUG?] Fenix 7 Solar bug in watch face with solar intensity graph

Hi,

i switched from a Fenix 6 Solar to the Fenix 7 Solar and really liked the watch face showing a history of the solar intensity.

I couldn't find the line chart for the watch face on the Fenix 7 anymore. Instead there's a bar chart.

However, that seems to be buggy (or I don't unterstand it). These bars keep appearing and disappearing. E.g. the watch was in direct sunlight for 30 minutes and then it was dark. So I'd expect a high bar to gradually move to the end with every hour passing. However, for 10-15 minutes, the bar disappears just to appear again and disappear again while gradually moving to the end.

Can someone confirm that this is a bug? If not, can please someone explain that graph?

Thanks