I can not replicate the bug...
But I find another bug : the Global search does not retrieve any result... (though there are indeed some results in the forums content...)
By the way, the message stating « Pas de résultat » – in French : no result – does not provice any hint about other ways to find information in the Moodle.org website … Maybe the message could be extended to give such an hint (for instance : « You may also try the Google search on the whole site »).
--------------------------------------------
I went to : https://moodle.org/course/view.php?id=5
Global search
https://moodle.org/search/index.php
I searched for :
wiktion*
I had no results...
https://moodle.org/search/index.php?q=wikt*&context=53
https://moodle.org/mod/forum/search.php?id=5
or
https://moodle.org/mod/forum/search.php?id=5&search=
I typed :
wiktion
Right now, there are 28 results.