xfce4-display-settings showing second monitor both active and inactive?!?

Might be related to #188 (closed) ?

I have a Dell Precision 7560/0Y1R4H, BIOS 1.34.0 08/12/2024 with Dock with Dual USB-c Dell dock.

I've always had random of troubles with xfce4-display-settings, the more frequent being when I connect the dock (on which 2nd monitor is attached as Display port):

• The second monitor is not detected
• The second monitor is detected but the configuration I've saved is not applied
• The configuration is detected and configuration applied, but the second monitor is put in diagonal top right of the main/LVDS screen instead of on top of the main (LVDS) screen.
• My configuration is saved but disappears from the menu (generally happens when previous bug occurs, I set up everything correctly again and say 'yes' when I'm asked if I update the config)
  This still occurs after years of reporting the bugs... In the end I have to reconfigure everything manually every time I plug/unplug the dock... PitA (makes me - a FLOSS defender for decades - wander how to defend linux vs. Windows/Mac these days)...

Whatever... this time I write for another problem: Since a few months, the second monitor is detected, but not activated and not activable at all... The attached screenshot shows what happens when I toggle the switch to activate the monitor: the switch at top right shows the monitor as activated, whereas the drawing at left remains displaying the monitor as disactivated!?! (the second being right: the monitor does not activate at all). Using xrandr --auto --output <the second monitor> or disconnecting the plug multiple times ends up working but is really PitA (knowing that this is in addition to previously cited bugs :( )

It seems xfce4-display-settings does not use xrandr as a backend, which makes me wonder why?