xfce4-notifyd volume change not longer popup notification bubble

Since about a week I mis the notification bubble when changing volume or pluggin my headphone. I'am runnung ubuntu bionic with pure xfce4-session, meaning metapackage xubuntu-desktop is not on my system.

    dbus-monitor --session interface='org.freedesktop.Notifications'
    signal time=1565429537.386265 sender=org.freedesktop.DBus -> destination=:1.73 serial=2 path=/org/freedesktop/DBus; interface=org.freedesktop.DBus; member=NameAcquired
       string ":1.73"
    signal time=1565429537.386395 sender=org.freedesktop.DBus -> destination=:1.73 serial=4 path=/org/freedesktop/DBus; interface=org.freedesktop.DBus; member=NameLost
string ":1.73"

Nothing listed after pluggin my headphone in or after command

pactl set-sink-volume 0 100%

After sending notify-send test

method call time=1565430913.692873 sender=:1.74 -> destination=:1.27 serial=6 path=/org/freedesktop/Notifications; interface=org.freedesktop.Notifications; member=GetServerInformation
method call time=1565430913.693595 sender=:1.74 -> destination=:1.27 serial=7 path=/org/freedesktop/Notifications; interface=org.freedesktop.Notifications; member=Notify
   string "notify-send"
   uint32 0
   string ""
   string "test"
   string ""
   array [
   ]
   array [
      dict entry(
         string "urgency"
         variant             byte 1
      )
   ]
   int32 -1
signal time=1565430923.336805 sender=:1.27 -> destination=(null destination) serial=23 path=/org/freedesktop/Notifications; interface=org.freedesktop.Notifications; member=NotificationClosed
   uint32 4
   uint32 1

Searching in journal

journalctl -b --user -u 

    dbus.service | grep notifyd
    Aug 10 10:49:56 beelzemon dbus-daemon[1916]: [session uid=1000 pid=1916] Activating via systemd: service name='org.freedesktop.Notifications' unit='xfce4-notifyd.service' requested by ':1.17' (uid=1000 pid=2062 comm="xfce4-power-manager " label="unconfined")

and

journalctl -b --user -u xfce4-notifyd
-- Logs begin at Sat 2019-07-27 22:58:00 CEST, end at Sat 2019-08-10 11:32:17 CEST. --
Aug 10 10:49:57 beelzemon systemd[1863]: Starting XFCE notifications service...
Aug 10 10:49:58 beelzemon systemd[1863]: Started XFCE notifications service.

and

systemctl --user list-dependencies default.target
default.target
● └─basic.target
●   ├─paths.target
●   ├─sockets.target
●   │ ├─dbus.socket
●   │ ├─dirmngr.socket
●   │ ├─gpg-agent-browser.socket
●   │ ├─gpg-agent-extra.socket
●   │ ├─gpg-agent-ssh.socket
●   │ └─gpg-agent.socket
●   └─timers.target

status von service

systemctl --user status xfce4-notifyd.service 
● xfce4-notifyd.service - XFCE notifications service
   Loaded: loaded (/usr/lib/systemd/user/xfce4-notifyd.service; static; vendor preset: enabled)
   Active: active (running) since Sat 2019-08-10 10:49:58 CEST; 1h 14min ago
 Main PID: 2145 (xfce4-notifyd)
   CGroup: /user.slice/user-1000.slice/[email protected]/xfce4-notifyd.service
           └─2145 /usr/lib/i386-linux-gnu/xfce4/notifyd/xfce4-notifyd

Aug 10 10:49:57 beelzemon systemd[1863]: Starting XFCE notifications service...
Aug 10 10:49:58 beelzemon systemd[1863]: Started XFCE notifications service.

I can't see any errors.

Note sound works well, other notification like guake are working.

sorry for so much text.

Edit, pulseaudio-plugin is configured, to send a notification if volume change.

Package xfce4-volumed is not on my system.

  apt list --installed | egrep 'volumed|pulseaudio|pavucontrol'

WARNING: apt does not have a stable CLI interface. Use with caution in scripts.

gstreamer1.0-pulseaudio/bionic-updates,now 1.14.5-0ubuntu1~18.04.1 i386 [installed,automatic]
osspd-pulseaudio/bionic,now 1.3.2-9 i386 [installed,automatic]
pavucontrol/bionic,now 3.0-4 i386 [installed,automatic]
pulseaudio/bionic-updates,now 1:11.1-1ubuntu7.2 i386 [installed]
pulseaudio-module-bluetooth/bionic-updates,now 1:11.1-1ubuntu7.2 i386 [installed]
pulseaudio-utils/bionic-updates,now 1:11.1-1ubuntu7.2 i386 [installed,automatic]
xfce4-pulseaudio-plugin/bionic,now 0.4.1-0ubuntu1 i386 [installed]

pulseaudio is configured for usersesssion.

ps -ef | grep pulse
alex      7316     1  0 15:21 ?        00:00:00 /usr/bin/pulseaudio --start --log-target=syslog
alex      7347  1991  0 15:22 ?        00:00:01 /usr/lib/i386-linux-gnu/xfce4/panel/wrapper-2.0 /usr/lib/i386-linux-gnu/xfce4/panel/plugins/libpulseaudio-plugin.so 22 10485802 pulseaudio PulseAudio-Modul Die Lautst??rke des PulseAudio-Klangsystems anpassen
alex      7414  3936  0 15:32 pts/4    00:00:00 grep --color=auto pulse

P:S error is not in /home. Testuser and guest-session same.