Ldap stuck in case of wrong username?

Hello,
I followed the " https://github.com/jitsi/jitsi-meet/wiki/LDAP-Authentication#ldap-authentication-for-jitsi-meet-via-ldap2 ".

I’m Using the LDAP2 authentication (because Cyrus_ldap seems to be problematic with prosody 0.11 and LUA 5.2. Some modules are not present or stays in 5.1 folders)

For me, authentication is working fine with ldap2 when username and password are corrects.
It’s sound goog when Username is correct and password is Wrong : a message show the error and the user can re-try.

But in case of mistake in the username (if user doesn’t exist in ldap), a popup appears with “connecting” and remains bloked. Nothing else happens.

the ERR log show this :

May 03 17:13:43 mod_bosh        error   Traceback[bosh]: /usr/lib/prosody/modules/ldap.lib.lua:218: attempt to index local 'attribs' (a nil value)
stack traceback:
/usr/lib/prosody/modules/ldap.lib.lua:218: in function 'singlematch'
/usr/lib/prosody/modules/ldap.lib.lua:187: in function </usr/lib/prosody/modules/ldap.lib.lua:179>
(...tail calls...)
/usr/lib/prosody/modules/mod_auth_ldap2/mod_auth_ldap2.lua:54: in function 'plain_test'
/usr/lib/prosody/util/sasl/plain.lua:75: in function </usr/lib/prosody/util/sasl/plain.lua:39>
(...tail calls...)
/usr/lib/prosody/modules/mod_saslauth.lua:77: in function </usr/lib/prosody/modules/mod_saslauth.lua:66>
(...tail calls...)
/usr/lib/prosody/util/events.lua:79: in function </usr/lib/prosody/util/events.lua:75>
(...tail calls...)
/usr/lib/prosody/core/stanza_router.lua:142: in function 'dispatch_stanza'
/usr/lib/prosody/modules/mod_bosh.lua:305: in function 'func'
/usr/lib/prosody/util/async.lua:127: in function </usr/lib/prosody/util/async.lua:125>
stack traceback:
/usr/lib/prosody/util/async.lua:211: in function 'run'
/usr/lib/prosody/modules/mod_bosh.lua:447: in function 'cb_handlestanza'
/usr/lib/prosody/util/xmppstream.lua:182: in function </usr/lib/prosody/util/xmppstream.lua:162>
[C]: in function 'parse'
/usr/lib/prosody/util/xmppstream.lua:282: in function 'feed'
/usr/lib/prosody/modules/mod_bosh.lua:133: in function '?'
/usr/lib/prosody/util/events.lua:79: in function </usr/lib/prosody/util/events.lua:75>
(...tail calls...)
/usr/lib/prosody/net/http/server.lua:228: in function </usr/lib/prosody/net/http/server.lua:176>
[C]: in function 'xpcall'
/usr/lib/prosody/net/http/server.lua:108: in function 'process_next'
/usr/lib/prosody/net/http/server.lua:124: in function 'success_cb'
/usr/lib/prosody/net/http/parser.lua:177: in function 'feed'
/usr/lib/prosody/net/http/server.lua:155: in function </usr/lib/prosody/net/http/server.lua:154>
(...tail calls...)
/usr/lib/prosody/net/server_select.lua:915: in function </usr/lib/prosody/net/server_select.lua:899>
[C]: in function 'xpcall'
/usr/bin/prosody:80: in function 'loop'
/usr/bin/prosody:90: in main chunk
[C]: in ?

Is there a solution resolv this pb ?
Thanks a lot by advance !
(Debian 10, Prosody 0.11.2, LUA 5.2)