Hi there,
Sorry that the Hue/Saturation box closes when you select an area for sampling in Photoshop.
Which version of Photoshop are you using and what is your computer's OS?
Would you mind try resetting the Photoshop preferences?
Press and hold Alt+Control+Shift (Windows) or Option+Command+Shift (Mac OS) as you start Photoshop. You are prompted to delete the current settings. The new preferences files are created the next time you start Photoshop. See: https://helpx.adobe.com/au/photoshop/using/preferences.html
Let us know how it goes.
Thanks,
Akash