Hello, On a brand new Debian 11, I don't install any packages during install. Then I install the following packages : apt-get install autoconf libtool pkg-config libcurl4-openssl-dev uuid-dev libssl-dev build-essential libtool-bin unzip libsqlite3-dev libpcre3-dev libspeex-dev libspeexdsp-dev libedit-dev python3-dev libsndfile-dev liblua5.2-dev libsqlite3-dev yasm zip libtiff-dev vim net-tools ssh Using git I take the sources of version v1.10.7 Then I take the sources of sofia and spandsp cd sofia-sip ./bootstrap.sh ./configure make make install cd spandsp-master ./bootstrap.sh ./configure make make install cd freeswitch ./bootstrap.sh -j (cp modules.conf freeswitch) ./configure make make install LD_LIBRARY_PATH=/usr/local/lib export LD_LIBRARY_PATH and run : /usr/local/freeswitch/bin/freeswitch -nonat -u root I don't do anything else, I keep the default config, I don't change anything. Just compiling... After launching freeswitch, I connect with fs_cli After the connection, hat the first command: show calls for example randomly, 50% of time, fs_cli freezes and becomes unresponsive. I did it, on several different servers here are the weirdest details... : For fs_cli hanging, there must be no activity on freeswitch. I run an fs_cli and it freezes. I run on a second console fs_cli and it freezes. I launch another fs_cli which does not freeze… and I do a “log 1 hello” This makes a trace, and all the fs_cli unfreeze…. With gdb I saw, fs_cli hangs in mutex locks I reproduce this on several debian 11.5, but the same source files compiling and work fine on debian 10.13 Do you have any ideas ?? Thanks Additional Information If anyone wants to reproduce. Here is the list of my module.conf applications/mod_commands applications/mod_conference applications/mod_distributor applications/mod_dptools applications/mod_esf applications/mod_expr applications/mod_hash applications/mod_spandsp applications/mod_test dialplans/mod_dialplan_xml endpoints/mod_loopback endpoints/mod_sofia event_handlers/mod_cdr_csv event_handlers/mod_event_socket formats/mod_local_stream formats/mod_native_file formats/mod_sndfile formats/mod_tone_stream languages/mod_lua loggers/mod_console loggers/mod_logfile loggers/mod_syslog timers/mod_posix_timer timers/mod_timerfd I used debian xen domu with the dom0 on debian 11 and on debian 10. Always the same thing happens. Work on domu debian 10 and hang on domu debian 11.