Cannot start IRC channel group chat

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Versions

OS: Windows 10 x64
Gajim version: 1.4.0-dev1
GTK version: 3.24.25
Python-nbxmpp version: 3.0.0-dev1

Steps to reproduce the problem

Register on IRC transport (for example irc2.jabber.hot-chilli.net), setup a channel by adding it as a contact (#foobar2000\40chat.freenode.net\3a6697)
Open Gajim > Start / Join Chat...
In the list choose the created contact

Expected behavior

Group chat opens

Actual behavior

A window with the following message opens: Address does not belong to a group chat server

I managed to open a group chat only by using a bookmark, and checking Autojoin. It seems that there is no other way to start a Group chat on an IRC channel.