Yesterday I have upgraded Bookworm to Trixie.
And today several times I have "lost" my panels.

I have a computer with Intel i7-1400K and I use built in Intel UHD Graphics 770
and two monitors connected to HDMI and DisplayPort sockets.
In my configuration I use three instances of xfce4-panel:
Panel 0 - horizontal, never hide on HDMI-1 (actualy DisplayPort)
Panel 1 - left side, never hide on HDMI-1 (actualy DisplayPort)
Panel 2 - horizontal, never hide  on HDMI-2

After logging in it works fine.
But after waking up from a screen lock only one panel is visible.
Configuration is held for all of them correctly
(at least what I see in the panel config is correcct)
but only "Panel 2" is actually visible (and working) on HDMI-2.
Panels 0 and 1 are invlisible.
At the same time windows of all other applications are on their places
on correct monitors (both are working).
Swiching hide never to other values and back does not help.
The only way I found to reveal all panels is to kill xfce4-panel process
and start it again from a terminal.

With Best Regards,
    Jerzy