I'll file a new bug report when I have a bit of time and put the link in a comment here when it's done.
I've realized now that this new bug as I'm seeing it is actually not contingent on Suspend taking place. If I simply go to menu "Lock", I get a black screen. Moving the mouse or otherwise triggering the unlock screen instead gives an image of the Desktop with no interaction possible except moving the cursor. Going to a different TTY and then back brings up the lock screen.
I'll file a new bug report when I have a bit of time and put the link in a comment here when it's done.
I've realized now that this new bug as I'm seeing it is actually not contingent on Suspend taking place. If I simply go to menu "Lock", I get a black screen. Moving the mouse or otherwise triggering the unlock screen instead gives an image of the Desktop with no interaction possible except moving the cursor. Going to a different TTY and then back brings up the lock screen.