A terminal appears after any lightdm session

[Freiklite]

Hi,
The Xubuntu 20.04 Release displays a terminal for two or three seconds after the lightdm session.
Then the desktop appears normaly.
Which file drives the process?
Can I rewrite it?
Thanks very much for your help,
D.B.

N.B.:
$ uname -a
Linux SATELLITE-C70D-B 5.4.0-48-generic #52-Ubuntu SMP Thu Sep 10 10:58:49 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux

~$ dpkg --status lightdm
Package: lightdm
Status: install ok installed

Hardware:
Toshiba SATELLITE-C70D-B

[Freiklite]

This excerpt touches upon the xfce4 theme with regard to xubuntu running process.
The "pstree command" says:
├─2*[kerneloops]
├─lightdm─┬─Xorg───12*[{Xorg}]
│ ├─lightdm─┬─xfce4-session─┬─Thunar───2*[{Thunar}]
│ │ │ ├─agent───2*[{agent}]
│ │ │ ├─applet.py
│ │ │ ├─blueman-applet───3*[{blueman-appl+
│ │ │ ├─kdeconnectd───5*[{kdeconnectd}]
│ │ │ ├─nm-applet───3*[{nm-applet}]
│ │ │ ├─polkit-gnome-au───2*[{polkit-gnom+
│ │ │ ├─ssh-agent
│ │ │ ├─update-notifier───3*[{update-noti+
│ │ │ ├─xfce4-panel─┬─panel-1-whisker───2+
│ │ │ │ ├─panel-4-systray───2+
│ │ │ │ ├─panel-5-notific───2+
│ │ │ │ ├─panel-8-power-m───2+
│ │ │ │ ├─panel-9-pulseau───2+
│ │ │ │ ├─redshift-gtk─┬─reds+
│ │ │ │ │ └─2*[{+
│ │ │ │ └─2*[{xfce4-panel}]
│ │ │ ├─xfce4-terminal─┬─4*[bash]
│ │ │ │ ├─bash───pstree
│ │ │ │ └─2*[{xfce4-termin+
│ │ │ ├─xfdesktop───2*[{xfdesktop}]
│ │ │ ├─xfwm4───13*[{xfwm4}]
│ │ │ ├─xiccd───2*[{xiccd}]
│ │ │ ├─xscreensaver
│ │ │ ├─zeitgeist-datah───6*[{zeitgeist-d+
│ │ │ └─2*[{xfce4-session}]
│ │ └─2*[{lightdm}]
│ └─2*[{lightdm}]
├─networkd-dispat

The bug may be at that level:
─lightdm─┬─xfce4-session─┬─Thunar───2*[{Thunar}]

Thank you for your attention.
Any suggestion is welcome.

[halogen2]

In Settings > Session and Startup, do you have a "Saved Sessions" tab?
What do you have enabled under Application Autostart?