just like the discussion title, lets make to the point now... the bug make my Laptop can't do Sleep Mode now. its relate to Fn + F7 combo, so what should i do?
Which model do you have and which browser are you using?
just press F7 button only.
there are other ways to enable turn caret browsing on, see below links
How to Turn ON Caret Browsing in Windows 10 all APPS (saransaro.com)
3 Ways to Turn Caret Browsing on in IE on Windows 10 (isunshare.com)