What to do when Xcode’s predictions don’t show up?

Personal Memo on November 2020

System version in this article: Xcode Version 12.0.1

1. Navigation on Xcode > Preferences > “Text Editing” > Select “Editing” in the menu bar
2. Uncheck “Suggest completions while typing”.
3. Quit Xcode with “Quit Xcode”
4. Launch Xcode again.
5. Go to Xcode > Preferences > Text Editing in the menu bar again
6. Check “Suggest completions while typing”.