Can't connect to Pulseaudio after user change on Lubuntu 20.04

[Tos]

On fresh install of Lubuntu 20.04:
- First login after Computer startup, no sound problem.
- User Account logout and login to another account => Very often, the sound is off (with a prohibited sign instead of the speaker in the dashboard).
And the status of Pulse audio is "connecting" when I call pavucontrol.

The way to get the sound again is to launch pulseaudio in a terminal or to reboot the computer.
---
ProblemType: Bug
ApportVersion: 2.20.11-0ubuntu27
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: maryline 2909 F.... pulseaudio
CasperMD5CheckResult: skip
DistroRelease: Ubuntu 20.04
InstallationDate: Installed on 2020-04-24 (5 days ago)
InstallationMedia: Lubuntu 20.04 LTS "Focal Fossa" - Release amd64 (20200423)
Package: pulseaudio 1:13.99.1-1ubuntu3
PackageArchitecture: amd64
ProcVersionSignature: Ubuntu 5.4.0-26.30-generic 5.4.30
PulseList: Error: command ['pacmd', 'list'] failed with exit code 1: No PulseAudio daemon running, or not running as session daemon.
Tags: focal
Uname: Linux 5.4.0-26-generic x86_64
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups:

_MarkForUpload: True
dmi.bios.date: 06/13/2006
dmi.bios.vendor: IBM
dmi.bios.version: 2EKT37AUS
dmi.board.name: IBM
dmi.board.vendor: IBM
dmi.chassis.asset.tag: �������������������������
dmi.chassis.type: 4
dmi.chassis.vendor: IBM
dmi.modalias: dmi:bvnIBM:bvr2EKT37AUS:bd06/13/2006:svnIBM:pn9210WD5:pvrThinkCentreM52:rvnIBM:rnIBM:rvr:cvnIBM:ct4:cvr:
dmi.product.name: 9210WD5
dmi.product.version: ThinkCentre M52
dmi.sys.vendor: IBM
modified.conffile..etc.pulse.default.pa: [modified]
mtime.conffile..etc.pulse.default.pa: 2020-04-24T17:22:11.318971

[Ubuntu Foundations Team Bug Bot (crichton)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. It seems that your bug report is not filed about a specific source package though, rather it is just filed against Ubuntu in general. It is important that bug reports be filed about source packages so that people interested in the package can find the bugs about it. You can find some hints about determining what package your bug might be about at https://wiki.ubuntu.com/Bugs/FindRightPackage. You might also ask for help in the #ubuntu-bugs irc channel on Freenode.

To change the source package that this bug is filed about visit https://bugs.launchpad.net/ubuntu/+bug/1875684/+editstatus and add the package name in the text box next to the word Package.

[This is an automated message. I apologize if it reached you inappropriately; please just reply to this message indicating so.]

[Tos (soto-patrick)]

I don't know exactly if it comes from the pulseaudio package or from the session manager package (sddm)

[Sebastien Bacher (seb128)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. Please execute the following command, as it will automatically gather debugging information, in a terminal:

  apport-collect 1875684

When reporting bugs in the future please use apport by using 'ubuntu-bug' and the name of the package affected. You can learn more about this functionality at https://wiki.ubuntu.com/ReportingBugs.

[Tos (soto-patrick)]

apport information

[Tos (soto-patrick)]

apport information

[Tos (soto-patrick)]

apport information

[Tos (soto-patrick)]

apport information

[Tos (soto-patrick)]

apport information

[Daniel van Vugt (vanvugt)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. This particular bug has already been reported and is a duplicate of bug 1814964, so it is being marked as such. Please look at the other bug report to see if there is any missing information that you can provide, or to see if there is a workaround for the bug. Additionally, any further discussion regarding the bug should occur in the other report. Feel free to continue to report any other bugs you may find.