I've searched for bugs related to the specific problems I've been having, and I've not been able to find anything that describes what I'm seeing.
I have an HP EliteBook 840 that also comes with an UltraDock, to which I've plugged-in two external monitors and I use in conjunction with the built-in laptop display.
What Fedora distro are you using?
Does this laptop have multiple GPUs? what GPU is it etc.
You probably should file a bug against the primary GPU with the dmesg.
Issue #2: When I undock my laptop while logged-in, Gnome Shell just crashes. When I redock after the laptop has been started when unconnected, one of the two external monitors start-up (the one connected by VGA), but not the one connected by a DisplayPort connection. And, recently (but not when I first started using this laptop with the dock, which was about a month ago), now when I start-up with the laptop docked and both external monitors connected, both external monitors will be active, but the built-in display will show nothing. Gnome Shell reports the built-in display is active, but will not display anything unless I deactivate it and reactivate it via the settings "Displays" utility.
This sounds like MST releated but I can't say without more info.
Dave.