Thanks to poster on page 2 andylew0 for suggesting turning off every setting app by app in Siri and changing language. This is the ONLY fix that worked for me short of a full reset or setting up phone as new. Thank you! It took hours to manually turn off every app in the list but that and switching language worked a treat.
recap:
Fixed! Spotlight Search
After days of frustration (tried restarts, toggling settings, language change, even full erase & restore – nothing worked), I finally fixed the Spotlight bug where it only finds apps but nothing else (no deep settings, contacts, messages, photos, etc.).
The combo that actually worked:
1. Changed iPhone Language to English (US) (Settings > General > Language & Region > iPhone Language).
2. Went to Settings > Siri & Search.
3. Turned OFF every single option at the top (Suggest Apps Before Searching, Allow Notifications, Show in App Library, Show When Sharing, Show Listening Suggestions).
4. Then, for every individual app in the list below, turned OFF all options (Show App in Search, Show Content in Search, etc.).
5. Restarted the phone.
6. Spotlight immediately started showing deep results again (settings shortcuts, etc.).
7. Turned all the individual app search options back ON (while still on US English).
8. Restarted again and left it on Wi-Fi for a bit – everything still working perfectly.
9. Finally switched language back to English (UK) – restarted – and it’s still 100% fixed.
This seems to fully force-rebuild the corrupted content index that gets stuck on some devices.