Docker meet second participant breaks conference

hi there,

i have an docker-base jitsi.
when a second person connects, the meeting breaks.
what i see in logs is posted down.

its the docker on a centos 7 with a public-ip (4 and 6)

Jicofo 2020-04-21 09:02:24.558 INFO: [37] org.jitsi.jicofo.Bridge.log() Video stream count for: jvb@auth.meet.jitsi/g7nTGW3x: 4
Jicofo 2020-04-21 09:02:24.561 WARNING: [75] org.jitsi.jicofo.JvbDoctor.log() Health check failed on: jvb@auth.meet.jitsi/g7nTGW3x error: java.lang.Exception: Address discovery through STUN failed
Jicofo 2020-04-21 09:02:24.561 INFO: [45] org.jitsi.jicofo.BridgeSelector.log() Removing JVB: jvb@auth.meet.jitsi/g7nTGW3x
Jicofo 2020-04-21 09:02:24.562 INFO: [45] org.jitsi.jicofo.JvbDoctor.log() Stopping health-check task for: jvb@auth.meet.jitsi/g7nTGW3x
Jicofo 2020-04-21 09:02:24.562 SEVERE: [45] org.jitsi.jicofo.JitsiMeetConferenceImpl.log() One of our bridges failed: jvb@auth.meet.jitsi/g7nTGW3x
Jicofo 2020-04-21 09:02:24.562 INFO: [45] org.jitsi.jicofo.JitsiMeetConferenceImpl.log() Region info, conference=ff3275 octo_enabled= false: [[null, null]]
Jicofo 2020-04-21 09:02:24.562 INFO: [45] org.jitsi.jicofo.JitsiMeetConferenceImpl.log() Expiring channels for: fastflowersdissolvenicely@muc.meet.jitsi/a43578a0 on: Bridge[jid=jvb@auth.meet.jitsi/g7nTGW3x, relayId=null, region=null]
Jicofo 2020-04-21 09:02:24.563 INFO: [45] org.jitsi.jicofo.JitsiMeetConferenceImpl.log() Region info, conference=ff3275 octo_enabled= false: [[null]]
Jicofo 2020-04-21 09:02:24.563 INFO: [45] org.jitsi.jicofo.JitsiMeetConferenceImpl.log() Expiring channels for: fastflowersdissolvenicely@muc.meet.jitsi/ae1ccdda on: Bridge[jid=jvb@auth.meet.jitsi/g7nTGW3x, relayId=null, region=null]
Jicofo 2020-04-21 09:02:24.568 SEVERE: [45] org.jitsi.jicofo.JitsiMeetConferenceImpl.log() Can not invite participant – no bridge available.
Jicofo 2020-04-21 09:02:24.568 SEVERE: [45] org.jitsi.jicofo.JitsiMeetConferenceImpl.log() Can not invite participant – no bridge available.
Jicofo 2020-04-21 09:02:24.568 WARNING: [45] org.jitsi.jicofo.BridgeSelector.log() Unable to handle bridge event for: jvb@auth.meet.jitsi/g7nTGW3x
Jicofo 2020-04-21 09:02:24.568 WARNING: [45] org.jitsi.jicofo.BridgeSelector.log() Unable to handle bridge event for: jvb@auth.meet.jitsi/g7nTGW3x

any ideas?