When typing in the search box at the top of any page or on Special:Search, the suggestions only appear once you have typed the full title (so they're practically useless at that point). I remember that the suggestions used to come up.
Steps to replicate:
- Visit any page on the Cookie Clicker Wiki.
- Click on the search bar
- Start typing "Main Pa"...
❌: The suggestion does not come up. ("Main Page")
- Finish typing "Main Page"
✔: The suggestion comes up. ("Main Page")