"Colours" panel not working correctly

Since the last update of Plasma 5.21 I notice a strange behaviour of the “Colours” panel in “System Settings”. Every example window shows the same colour for the selected background. It’s somehow annoying over time…
Does anyone have an idea what could have caused this?

Thank you in advance :grinning:

Seem to be the new standard properties now. Noticed the same behaviour on the example pictures at

You may consider this thread solved.