Color range eyedropper canceling when mouse is moved

Did the suggestion above help?
Feel free to reach out. Moving this thread from Bugs to Discussions for now.

Thanks,
Nishu

Make sure that the selection tool is active (v). If it is, look for any mouse utilities that are running, any expressions on the layer, or anything else that might be going on on the layer by pressing the "u" key twice to reveal all modified properties. 

If none of that helps, try updating your mouse drivers or settings, or try holding down Shift + Alt/Option + Ctrl/Cmnd when you launch After Effects and reset your preferences.