The problem is reproducible in your demo section: https://demos.telerik.com/blazor-ui/colorpicker/overview
I attached two short video clips showing the problem and the screenshots below.
Image 1: Open the Color Picker by clicking on it with the mouse. The picker dialog opens.
Image 2: Click with the mouse in the green area. You see a minor change in the RGBA fields, but no change in the color canvas.
Image 3: By clicking in the G field e.g. and changing the number with the down key from 46 to 45, the slider moves back to the blue area of it.
It seems to happen only with the first click onto the slider. With the second click and more it works like it should.
Best regards,
Hannes