Mobile Fulltext search behavior

Hi Folks,
I use the CBL version 3.0 in an iOS app.
I noticed that when I search for a string like “Recovery A” it returns all expected occurrences like “Recovery After” but when I add a new character ‘f’ to the search text above e.g. “Recovery Af”, the search result is empty. Any idea what that breaks here?
the results are correct if I look for something like “Recovery Pr” that in case it lists items like “Recovery Program”.

Thank you,
Kam

CBL is using SQLite FTS extension for FT Index and query. The result could be related to how SQLite does tokenizing and stemming. You may try the to use phase (with quote) and prefix () query such as '"Recovery Af"’ (Single Quote then Quote) to see if you can get more consistent result.