Spotlight search does not work properly on High Sierra
The following steps are reproducable on my mid-2015 15' macbook pro Retina. OS: High sierra. It's upgraded from Sierra.
(a) click the spotlight search icon on the right top of the screen. (b) type any text on the spotlight search text box shown on the screen.
Actual result: the spotlight search box disappears immediately following my typing in any one character. Other applications work well though. Any suggestion? Thank you.
MacBook Pro with Retina display, macOS High Sierra (10.13), upgrade from macOS Sierra