This is a vBulletin problem, not an LFPF problem.
The search algorithm rejects any short text, completely ignoring it.
That might make sense on a culinary forum, but on a photography forum where many products have short names,
like the Sinar F2 and other models, or Schneider XL lenses, this limitation makes no sense and causes greatly
inflated search results.
Is there a configuration option that would remove this limitation?
The only solution is to use Google site search, which does not reject short terms.