eyedropper of version 21.2 could not take to correct colour on screen

After I installed with new version 21.2, I used eyedropper to take the color from picture. But I could not get the correctly color such as I need black on screen but I got gray (drop 50%, I tried with Red as well which was same problem). Now I had already uninstalled and go back to last version.

Please kindly advise for solution for reinstall new version. Thank you for your support in advance. 🙂