fts-solr autoindex issue in public mailbox

[maks]

Hello everyone,

I have a public mailbox:
   /var/mail/example.com/public/public_mailbox

with "Public/" namespace set up in config file.

When i move message from user's INBOX to one of mailboxes inside Public/ 
(for example Public/archive), i'm getting "indexer-worker: Info: Indexed 
0 messages in Public/archive" in logs and i can't find the message 
through the FTS search.
If i move the message back from Public/archive into personal mailbox the 
message is indexed by indexer-worker "indexer-worker: Info: Indexed 1 
messages in temp_folder"

If i perform "doveadm index Public/archive" then the message is added to 
the index.

Dovecot version: 2.2.9
FTS backend: Solr

fts_autoindex = yes


Searching through localhost:8983/solr/collection1 gives the same result.