[Dovecot] doveadm search doesn't update fts

[metro_domain_admin at fastmail.fm]

Hello,

Doveadm search is failing to update our Squat indexes. The search itself
works fine but the dovecot.index.search* files remain unchanged. I
tried:

doveadm search -u test mailbox INBOX body sometext
doveadm search -u test mailbox INBOX text sometext

I also tried the exact syntax Timo expressed in an earlier post:

doveadm search -A body asdf

If I run the same search through IMAP, the index files update as
expected. The searches finish with a clean exit status and nothing shows
up in the logs. I upgraded from 2.0.0 to 2.0.11 but the problem remains. 

>From doveconf -n:

plugin {
  fts = squat
}

protocol imap {
  mail_max_userip_connections = 16
  mail_plugins = $mail_plugins fts fts_squat
}

Thank you,
Tony