Colorsync Utility calculator picks colors only from Desktop background

I'm trying to use ColorSync Utility calculator on macOS Big Sur 11.6.5. And it doesn't work. I cannot pick a correct color. The color picker looks through any application windows disregarding them and picks only colors of the respective areas on the Desktop background behind those windows. The only app window which works is ColorSync Utility itself. How do I fix it and make it work?