Jitsi unstable version crashed from fresh installation on EC2 instance when the second user join the meeting

I use the unstable jitsi-meet installation based on the following link:

The system will crash when the 2nd person joinned the meeting.
I setup the system on Amazon EC2 with all related ports open.
My goal is to setup the 2nd jvb with loadbalance through muc. However, I cannot make it work with either the change from stable version or just install the unstable version.
Please help.

PS: Since the new user can only use two links, the domain info like meet.mydomain.com will be replaced with meet-mydomain-com

Prosody.log

Mar 25 17:02:38 conference-meet-mydomain-com:muc_domain_mapper warn Session filters applied
Mar 25 17:02:38 mod_bosh info New BOSH session, assigned it sid ‘1c201a9c-592e-4ddf-8e19-ef6e64b2ae1e’
Mar 25 17:02:38 bosh1c201a9c-592e-4ddf-8e19-ef6e64b2ae1e info Authenticated as 0dc19fe9-9f62-484c-a75a-54c5ef86e2a2@meet-mydomain-com
Mar 25 17:02:46 conference-meet-mydomain-com:muc_domain_mapper warn Session filters applied
Mar 25 17:02:46 mod_bosh info New BOSH session, assigned it sid ‘aab3226a-7821-4f20-9827-3b22228403f5’
Mar 25 17:02:46 boshaab3226a-7821-4f20-9827-3b22228403f5 info Authenticated as 9f38ae48-29b3-4e15-918e-ed6e8bd0ce09@meet-mydomain-com
Mar 25 17:02:47 boshaab3226a-7821-4f20-9827-3b22228403f5 info BOSH client disconnected
Mar 25 17:02:47 bosh1c201a9c-592e-4ddf-8e19-ef6e64b2ae1e info BOSH client disconnected

Jicofo.log

Jicofo 2020-03-25 17:02:40.369 INFO: [76] org.jitsi.jicofo.xmpp.FocusComponent.handleConferenceIq().401 Focus request for room: hello@conference-meet-mydomain-com
Jicofo 2020-03-25 17:02:40.369 INFO: [76] org.jitsi.jicofo.FocusManager.log() Created new focus for hello@conference-meet-mydomain-com@auth-meet-mydomain-com. Conference count 1,options:
Jicofo 2020-03-25 17:02:40.370 INFO: [76] org.jitsi.jicofo.JitsiMeetConferenceImpl.log() Lip-sync enabled in hello@conference-meet-mydomain-com
Jicofo 2020-03-25 17:02:40.370 INFO: [76] org.jitsi.jicofo.JitsiMeetConferenceImpl.log() Joining the room: hello@conference-meet-mydomain-com
Jicofo 2020-03-25 17:02:40.431 INFO: [127] org.jitsi.jicofo.ChatRoomRoleAndPresence.log() Chat room event ChatRoomMemberPresenceChangeEvent[type=MemberJoined sourceRoom=org.jitsi.impl.protocol.xmpp.ChatR$
Jicofo 2020-03-25 17:02:40.434 INFO: [127] org.jitsi.jicofo.ChatRoomRoleAndPresence.log() Granted owner to hello@conference-meet-mydomain-com/0dc19fe9
Jicofo 2020-03-25 17:02:40.434 INFO: [127] org.jitsi.jicofo.JitsiMeetConferenceImpl.log() Member hello@conference-meet-mydomain-com/0dc19fe9 joined.
Jicofo 2020-03-25 17:02:47.192 INFO: [80] org.jitsi.jicofo.xmpp.FocusComponent.handleConferenceIq().401 Focus request for room: hello@conference-meet-mydomain-com
Jicofo 2020-03-25 17:02:47.331 INFO: [127] org.jitsi.jicofo.ChatRoomRoleAndPresence.log() Chat room event ChatRoomMemberPresenceChangeEvent[type=MemberJoined sourceRoom=org.jitsi.impl.protocol.xmpp.ChatR$
Jicofo 2020-03-25 17:02:47.331 INFO: [127] org.jitsi.jicofo.JitsiMeetConferenceImpl.log() Member hello@conference-meet-mydomain-com/9f38ae48 joined.
Jicofo 2020-03-25 17:02:47.333 WARNING: [127] org.jitsi.jicofo.bridge.BridgeSelectionStrategy.log() Failed to select initial bridge for participantRegion=null
Jicofo 2020-03-25 17:02:47.333 SEVERE: [127] org.jitsi.jicofo.JitsiMeetConferenceImpl.log() Can not invite participant – no bridge available.
Jicofo 2020-03-25 17:02:47.333 WARNING: [127] org.jitsi.jicofo.bridge.BridgeSelectionStrategy.log() Failed to select initial bridge for participantRegion=null
Jicofo 2020-03-25 17:02:47.333 SEVERE: [127] org.jitsi.jicofo.JitsiMeetConferenceImpl.log() Can not invite participant – no bridge available.
Jicofo 2020-03-25 17:02:47.587 INFO: [127] org.jitsi.jicofo.ChatRoomRoleAndPresence.log() Chat room event ChatRoomMemberPresenceChangeEvent[type=MemberLeft sourceRoom=org.jitsi.impl.protocol.xmpp.ChatRoo$
Jicofo 2020-03-25 17:02:47.587 INFO: [127] org.jitsi.jicofo.JitsiMeetConferenceImpl.log() Member hello@conference-meet-mydomain-com/9f38ae48 is leaving
Jicofo 2020-03-25 17:02:47.588 INFO: [127] org.jitsi.jicofo.JitsiMeetConferenceImpl.log() Removed participant: true, hello@conference-meet-mydomain-com/9f38ae48
Jicofo 2020-03-25 17:02:47.740 INFO: [127] org.jitsi.jicofo.ChatRoomRoleAndPresence.log() Chat room event ChatRoomMemberPresenceChangeEvent[type=MemberLeft sourceRoom=org.jitsi.impl.protocol.xmpp.ChatRoo$
Jicofo 2020-03-25 17:02:47.740 INFO: [127] org.jitsi.jicofo.ChatRoomRoleAndPresence.log() Owner has left the room !
Jicofo 2020-03-25 17:02:47.740 INFO: [127] org.jitsi.jicofo.JitsiMeetConferenceImpl.log() Member hello@conference-meet-mydomain-com/0dc19fe9 is leaving
Jicofo 2020-03-25 17:02:47.741 INFO: [127] org.jitsi.jicofo.JitsiMeetConferenceImpl.log() Removed participant: true, hello@conference-meet-mydomain-com/0dc19fe9
Jicofo 2020-03-25 17:02:47.742 INFO: [127] org.jitsi.jicofo.FocusManager.log() Disposed conference for room: hello@conference-meet-mydomain-com conference count: 0

Jvb.log

JVB 2020-03-25 17:02:05.564 INFO: [18] org.jitsi.videobridge.Videobridge.log() CAT=stat create_conf,conf_id=f75517dd321b1fb9 conf_name=null,logging=false,conf_count=1,ch_count=0,v_streams=0
JVB 2020-03-25 17:02:05.584 INFO: [18] org.jitsi.videobridge.health.Health.log() Performed a successful health check in 20ms. Sticky failure: false
JVB 2020-03-25 17:02:12.304 INFO: [17] org.jitsi.videobridge.VideobridgeExpireThread.log() Running expire()
JVB 2020-03-25 17:02:15.585 INFO: [18] org.jitsi.videobridge.Videobridge.log() CAT=stat create_conf,conf_id=4c9180befe62bb53 conf_name=null,logging=false,conf_count=1,ch_count=0,v_streams=0
JVB 2020-03-25 17:02:15.599 INFO: [18] org.jitsi.videobridge.health.Health.log() Performed a successful health check in 14ms. Sticky failure: false
JVB 2020-03-25 17:02:25.599 INFO: [18] org.jitsi.videobridge.Videobridge.log() CAT=stat create_conf,conf_id=7314fc8614989652 conf_name=null,logging=false,conf_count=1,ch_count=0,v_streams=0
JVB 2020-03-25 17:02:25.614 INFO: [18] org.jitsi.videobridge.health.Health.log() Performed a successful health check in 15ms. Sticky failure: false
JVB 2020-03-25 17:02:35.615 INFO: [18] org.jitsi.videobridge.Videobridge.log() CAT=stat create_conf,conf_id=2a80428829926b1 conf_name=null,logging=false,conf_count=1,ch_count=0,v_streams=0
JVB 2020-03-25 17:02:35.631 INFO: [18] org.jitsi.videobridge.health.Health.log() Performed a successful health check in 16ms. Sticky failure: false
JVB 2020-03-25 17:02:45.631 INFO: [18] org.jitsi.videobridge.Videobridge.log() CAT=stat create_conf,conf_id=9d0d169360809029 conf_name=null,logging=false,conf_count=1,ch_count=0,v_streams=0
JVB 2020-03-25 17:02:45.646 INFO: [18] org.jitsi.videobridge.health.Health.log() Performed a successful health check in 15ms. Sticky failure: false
JVB 2020-03-25 17:02:55.646 INFO: [18] org.jitsi.videobridge.Videobridge.log() CAT=stat create_conf,conf_id=da1c76574772ee76 conf_name=null,logging=false,conf_count=1,ch_count=0,v_streams=0
JVB 2020-03-25 17:02:55.662 INFO: [18] org.jitsi.videobridge.health.Health.log() Performed a successful health check in 16ms. Sticky failure: false
JVB 2020-03-25 17:03:05.662 INFO: [18] org.jitsi.videobridge.Videobridge.log() CAT=stat create_conf,conf_id=489e8a94e33ba1d4 conf_name=null,logging=false,conf_count=1,ch_count=0,v_streams=0
JVB 2020-03-25 17:03:05.681 INFO: [18] org.jitsi.videobridge.health.Health.log() Performed a successful health check in 19ms. Sticky failure: false
JVB 2020-03-25 17:03:12.304 INFO: [17] org.jitsi.videobridge.VideobridgeExpireThread.log() Running expire()

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