Not found indexed word

Hello,

We are working on a projet in java 8 and we use the PostgreSQL 9.6 technology. Part of this project contains indexing and search, for that we user tsvector.
During the test we found that for a spécific word "Pepiniere" the result of the search is null, while the word is indexed in the data base.



If i search with the word Metz or Strasbourg, the word "Pepiniere" goes back well in the results.
Do you ahave an idea about this problèm ?

Cordialement,
JARRAYA Melek
Tel: 03 88 06 64 34