Conference_duration in docker fails on prosody can't generate certs

Hi,
we’re using jitsi in kubernetes infrastructure, so we are running jitsi based on docker images.
I wanted to use conference_duration component, so I configured as shown in https://github.com/jitsi/jitsi-meet/blob/master/doc/debian/jitsi-meet-prosody/prosody.cfg.lua-jvb.example
But after i added the last part

Component "conference_duration.our_xmpp_domain" "conference_duration_component"
    muc_component = "our_muc_xmpp_domain"

prosody wouldn’t generate certificates and shows some strange error prosody.log (2.4 KB)

Prosody version identifies itself as prosody-0.11.5-1stretch6

prosodyctl about

Prosody 0.11.5

# Prosody directories
Data directory:     /config/data
Config directory:   /config
Source directory:   /usr/lib/prosody
Plugin directories:
  /prosody-plugins/
  /prosody-plugins-custom
  /usr/lib/prosody/modules/


# Lua environment
Lua version:                    Lua 5.2

Lua module search paths:
  /usr/lib/prosody/?.lua
  /usr/local/share/lua/5.2/?.lua
  /usr/local/share/lua/5.2/?/init.lua
  /usr/local/lib/lua/5.2/?.lua
  /usr/local/lib/lua/5.2/?/init.lua
  /usr/share/lua/5.2/?.lua
  /usr/share/lua/5.2/?/init.lua

Lua C module search paths:
  /usr/lib/prosody/?.so
  /usr/local/lib/lua/5.2/?.so
  /usr/lib/x86_64-linux-gnu/lua/5.2/?.so
  /usr/lib/lua/5.2/?.so
  /usr/local/lib/lua/5.2/loadall.so

LuaRocks:               Not installed

# Network

Backend: epoll

# Lua module versions
lfs:            LuaFileSystem 1.6.3
lxp:            LuaExpat 1.3.0
socket:         LuaSocket 3.0-rc1
ssl:            0.7

Is this a bug on prosody side, or do we need to update Dockerfile to build updated image that handles this?
I noticed, that there is a change in aforementioned example file - conference_duration -> conferenceduration. Does this correct the situation?

so just to let you know, it was cause of this

Component "conference_duration.our_xmpp_domain" "conference_duration_component"

after removing underscore between conference and duration, the certificate was sucessfully generated.

Component "conferenceduration.our_xmpp_domain" "conference_duration_component"

I can see now that it was obvious, since component names should be dns compatible names.