Ticket subject loss on reply

[sdv]

Hi.

A Messaging System ticket subject changes to "none" on first reply.

You can reproduce this in demo (press "Reply" button):
https://www.directadmin.com:2222/CMD_TICKET?action=view&number=000000044&type=ticket

Expected behaviour: ticket subject stays the same for every ticket message.

DA version: 1.51.3