How to debug jicofo SEVERE "no bridge available" error?

/var/log/jitsi/jicofo.log:Jicofo 2020-08-16 11:15:28.441 SEVERE: [83] org.jitsi.jicofo.JitsiMeetConferenceImpl.log() Can not invite participant – no bridge available.

other log warnings and errors …

$ egrep -i ‘warn|err|severe’ /var/log/{jitsi,prosody}/*

/var/log/jitsi/jicofo.log:Jicofo 2020-08-16 11:14:11.206 INFO: [11] org.jitsi.impl.configuration.ConfigurationServiceImpl.log() failed to find jitsi-default-overrides.properties with class loader, will continue without it.
/var/log/jitsi/jicofo.log:Jicofo 2020-08-16 11:14:11.498 WARNING: [11] org.jitsi.jicofo.FocusManager.log() Jicofo ID is not set. Configure a valid value [1-65535] by setting org.jitsi.jicofo.SHORT_ID. Future versions will require this for Octo.
/var/log/jitsi/jicofo.log:Jicofo 2020-08-16 11:14:11.537 WARNING: [11] org.jitsi.jicofo.FocusManager.log() No dedicated JVB MUC XMPP connection configured - falling back to the default XMPP connection
/var/log/jitsi/jicofo.log:Jicofo 2020-08-16 11:14:11.967 WARNING: [11] org.jitsi.jicofo.bridge.JvbDoctor.log() JVB health-checks disabled
/var/log/jitsi/jicofo.log:Jicofo 2020-08-16 11:14:12.623 WARNING: [18] org.jitsi.impl.protocol.xmpp.OpSetSimpleCapsImpl.log() Failed to discover features for conferenceduration.jitsi.redacted.dom: XMPP error reply received from conferenceduration.jitsi.redacted.dom: XMPPError: service-unavailable - cancel
/var/log/jitsi/jicofo.log:Jicofo 2020-08-16 11:14:12.660 WARNING: [18] org.jitsi.impl.protocol.xmpp.OpSetSimpleCapsImpl.log() Failed to discover features for jitsi-videobridge.jitsi.redacted.dom: XMPP error reply received from jitsi-videobridge.jitsi.redacted.dom: XMPPError: service-unavailable - wait
/var/log/jitsi/jicofo.log:Jicofo 2020-08-16 11:14:12.687 WARNING: [18] org.jitsi.impl.protocol.xmpp.OpSetSimpleCapsImpl.log() Failed to discover features for focus.jitsi.redacted.dom: XMPP error reply received from focus.jitsi.redacted.dom: XMPPError: service-unavailable - wait
/var/log/jitsi/jicofo.log:Jicofo 2020-08-16 11:14:12.688 WARNING: [18] org.jitsi.impl.protocol.xmpp.OpSetSimpleCapsImpl.log() Failed to discover features for speakerstats.jitsi.redacted.dom: XMPP error reply received from speakerstats.jitsi.redacted.dom: XMPPError: service-unavailable - cancel
/var/log/jitsi/jicofo.log:Jicofo 2020-08-16 11:15:28.439 WARNING: [83] org.jitsi.jicofo.bridge.BridgeSelectionStrategy.log() Failed to select initial bridge for participantRegion=null
/var/log/jitsi/jicofo.log:Jicofo 2020-08-16 11:15:28.439 SEVERE: [83] org.jitsi.jicofo.JitsiMeetConferenceImpl.log() Can not invite participant – no bridge available.
/var/log/jitsi/jicofo.log:Jicofo 2020-08-16 11:15:28.441 WARNING: [83] org.jitsi.jicofo.bridge.BridgeSelectionStrategy.log() Failed to select initial bridge for participantRegion=null
/var/log/jitsi/jicofo.log:Jicofo 2020-08-16 11:15:28.441 SEVERE: [83] org.jitsi.jicofo.JitsiMeetConferenceImpl.log() Can not invite participant – no bridge available.
/var/log/jitsi/jvb.log:2020-08-16 11:14:12.165 WARNING: [12] org.glassfish.jersey.internal.inject.Providers.checkProviderRuntime: A provider org.jitsi.rest.Version registered in SERVER runtime does not implement any provider interfaces applicable in the SERVER runtime. Due to constraint configuration problems the provider org.jitsi.rest.Version will be ignored.
/var/log/jitsi/jvb.log:2020-08-16 11:14:12.166 WARNING: [12] org.glassfish.jersey.internal.inject.Providers.checkProviderRuntime: A provider org.jitsi.rest.Health registered in SERVER runtime does not implement any provider interfaces applicable in the SERVER runtime. Due to constraint configuration problems the provider org.jitsi.rest.Health will be ignored.
/var/log/prosody/prosody.log:Aug 16 11:14:12 conference.jitsi.redacted.dom:muc_domain_mapper warn Session filters applied
/var/log/prosody/prosody.log:Aug 16 11:14:12 jitsi-videobridge.jitsi.redacted.dom:component warn Component not connected, bouncing error for:
/var/log/prosody/prosody.log:Aug 16 11:14:12 focus.jitsi.redacted.dom:component warn Component not connected, bouncing error for:
/var/log/prosody/prosody.log:Aug 16 11:14:12 conference.jitsi.redacted.dom:muc_domain_mapper warn Session filters applied
/var/log/prosody/prosody.log:Aug 16 11:14:41 conference.jitsi.redacted.dom:muc_domain_mapper warn Session filters applied
/var/log/prosody/prosody.log:Aug 16 11:14:46 conference.jitsi.redacted.dom:muc_domain_mapper warn Session filters applied
/var/log/prosody/prosody.log:Aug 16 11:15:27 conference.jitsi.redacted.dom:muc_domain_mapper warn Session filters applied
/var/log/prosody/prosody.log:Aug 16 11:15:28 speakerstats.jitsi.redacted.dom:speakerstats_component warn A module has been configured that triggers external events.
/var/log/prosody/prosody.log:Aug 16 11:15:28 speakerstats.jitsi.redacted.dom:speakerstats_component warn Implement this lib to trigger external events.