Debian Bookworm Black Screen on Connect to :0 is locked

[markd89]

Debian Bookworm / Mate desktop

I'm using SSVNC to connect to x11vnc :0

This has worked in Debian buster and older.

If I connect to a logged-in and unlocked session then all works OK.

If I connect to a locked session, I get a black screen. Keys pressed do not elicit the login greeter.

In my testing (the remote host is beside me), I can unlock the session and then see the screen remotely. Of course, this is only testing. In practice, the computers are not beside each other.

Are there any settings or hacks needed to allow x11vnc to show the login/unlock dialog with LightDM?

Has anything changed in LightDM/Greeter/Bookworm to make changes necessary?

SSVNC, Remote SSH Command:

x11vnc -no6 -shared -display :0 -noxdamage -timeout 15 -xkb -skip_keycodes 187,188 -listen localhost -rfbport 5900 -rfbportv6 -1