Description of problem:
I don't know what happened. At one point I tried to join a call and didn't get any sound.
I tried mplayer in the command line; that complained about the audio device being stuck.

Sound returned after I rebooted the computer.

Version-Release number of selected component:
pipewire-pulseaudio-0.3.23-2.fc34

Additional info:
reporter:       libreport-2.14.0
backtrace_rating: 4
cgroup:         0::/user.slice/user-1000.slice/user/session.slice/pipewire-pulse.service
cmdline:        /usr/bin/pipewire-pulse
crash_function: client_cleanup_stream
executable:     /usr/bin/pipewire-pulse
journald_cursor: s=e515bd62c8254c03abf2ea63fbbcb301;i=7f318;b=fdfdb203fefd477cb08f515796306de6;m=1f81569fd;t=5bd40093181c1;x=5b38f0a365d4e69
kernel:         5.11.3-300.fc34.x86_64
rootdir:        /
runlevel:       N 5
type:           CCpp
uid:            1000

Truncated backtrace:
Thread no. 1 (6 frames)
 #0 client_cleanup_stream at ../src/modules/module-protocol-pulse/pulse-server.c:5496
 #1 pw_map_for_each at ../src/pipewire/map.h:196
 #2 on_client_cleanup at ../src/modules/module-protocol-pulse/pulse-server.c:5511
 #3 source_event_func at ../spa/plugins/support/loop.c:463
 #4 loop_iterate at ../spa/plugins/support/loop.c:308
 #5 pw_main_loop_run at ../src/pipewire/main-loop.c:158