FreeBSD/X11: Howto revive DisplayPort?

Using FreeBSD CURREN and FreeBSD STABLE/15.
Also, most systems are attached to a KVM switch, connected via DP.

Hosts booting all UEFI.

On hosts using X11/xdm GUI, switching forth and back to the output/host I want to use
DP does obviously not "lose" DP output, so after graphics has been initialized I'm able
to see the GUI.

The situation is completely different with plain consoles, provided by FreeBSD's EFI/UEFI
simple framebuffer device driver. Working on the console on one host, switching to
another host, working there and trying to switch back leaves me with no output anymore! I
see this behaviour with different types of KVM switches I have at hand.

Can this behaviour be changed, even with no X11?

Thanks in advance and wishes,

O. Hartmann