Display settings dialog is shown after turning screen off and on again

Since upgrading to Xfce 4.18, the display settings dialog is always shown after turning the screen off and on again. It looks like Xfce thinks the display is newly connected.

Workaround: Set the action for "When new displays are connected" to "Do nothing".

The IT Crowd came to my mind when filing this bug report. 😜
"Have you tried turning it off and on again?"