Continuing the discussion from Admin dashboard report reference guide:
dashboard_hidden_reports is an example of a setting with a “Search or create…” control field that doesn’t return any search results and instead requires an exact text entry:

AskBot explains:
The dashboard_hidden_reports setting is configured as a “list” with list_type set to “compact” and allow_any set to true. This configuration means:
- You can enter any report key, but there is not a pre-populated list of report keys to choose from.
- The search control for this setting does not fetch or suggest built-in report keys, so typing in partial or full report names will not return any search results, autocomplete, or suggestions.
- You must manually enter the correct report keys.
It’s not an ideal experience to try multiple searches and discover that nothing will work.
I’d suggest that such settings should either actually search a list of valid entries — choices:(defined), allow_any:false — or, where that’s impractical, omit “search” from the hint text.