Cyrus 3.0 FUZZY search not working after upgrade from 2.5

[Jesper Schmitz Mouridsen]

Hi List.

I some time ago upgraded my imapd to 3.0.1 on FreeBSD 11

y4 UID SEARCH RETURN (ALL) CHARSET utf-8 FUZZY SUBJECT test
y4 OK Completed (0 msgs in 0.000 secs)
y6 UID SEARCH RETURN (ALL) CHARSET utf-8 SUBJECT test
y6 OK Completed (625 msgs in 0.766 secs)

My understanding is that FUZZY in y4 should return all messages with 
subject 
containing 'test'? Note that y6 returns 625 messages without the FUZZY key 
word.

What could be wrong here, I'm not using xapian and have no search_engine 
set in 
imapd.conf