Multiple isolated jitsi instances on one machine

Hi
I want to make my multi domain jitsi installation on one machine.
jcfischer said they achieved “Pool of shared video-bridges (all front end instances share the same pool of videobridges) using the new MUC feature” - Working Multi Jitsi-meet / multi Videobridge setup
But i can’t find what that MUC feature is.
Followed really old advice from way back 2015:
[jitsi-dev] how to configure multiply jitsi-meet conferences on one server
I’ve got 2 jicofo instances with different domains, also second nginx subdomain with different config.js.
I can get to work my second domain when i’ll change "bridge: " in config.js JVB_HOSTNAME in /etc/jitsi/videobridge and add “Component jitsi-videobridge.domain.pl” to prosody config, but then the first domain gets the error.

The error in jicofo is: SEVERE: Can not invite participant – no bridge available.
and WARNING: Failed to select initial bridge for participantRegion=null
The error in console is: CONFERENCE FAILED: conference.videobridgeNotAvailable
Problem is, logs don’t even show anything useful. I need help where to look, but if you really want them:
JVB logs: https://pastebin.com/DAQiG1Le
JVB config: https://pastebin.com/kipjc6tc
Jicofo logs:https://pastebin.com/wwqwAZQL
Jicofo config: --domain=test3.pl --host=localhost --secret=secret --user_domain=auth.test3.pl --user_name=focus --user_password=password
Jitsi config.js: only added focus: ‘focus.test3.pl’, bridge: ‘jitsi-videobridge.test2.pl’
Prosody logs: https://pastebin.com/U0jMreBG
Prosody config(both domains): https://pastebin.com/WP44GAzf
Thanks for any help in advance.