Always disconnected just after login

I am always disconnected just after login to the conference.

my login/password works, no error.
No error in log files.

prosody.log :
May 23 23:28:40 boshf7d07e06-0434-4936-b293-e085830e7e90 info Authenticated as
May 23 23:28:42 warn Session filters applied
May 23 23:28:42 c2s56161260c240 info Client connected
May 23 23:28:42 c2s56161260c240 info Client disconnected: connection closed

I have installed jitsi on a debian server with host and guest authentications

I have followed the instructions according to :

below, chrome lines console after login :
2020-05-23T11:14:00.419Z [modules/xmpp/moderator.js] <u.parseSessionId>: Received sessionId: 05731b0d-c4a0-4756-a030-6d422f0a640d

2020-05-23T11:14:00.422Z [modules/xmpp/xmpp.js] <A.connectionHandler>: (TIME) Strophe disconnecting: 21121.520000000004

Logger.js:154 2020-05-23T11:14:00.424Z [modules/xmpp/strophe.util.js] <Object.r.Strophe.log>: Strophe: Disconnect was called because: undefined

it works fine in anonymous mode

Thank you for your help