Multi-Monitor Problems

[wdff]

Hi there!
My Virtualbox (W10 host, Ubuntu 18.04 guest) is behaving very strangely.
I have three screens and am constantly struggling to get them working with virtualbox.
i have changed the video adapter to VboxVGA, as all the others seemed to distort the picture (and not work either).
now i've had a pretty solid experience in the recent time with the EXACT setup that is failing now.
i have no idea what's wrong, i boot the VM up, 3 windows are opened, then 2 of them immediately close.
i can't reactivate them again, the menu button for each screen is just not responsive at all.
SOMETIMES it helps to shut everything down and restart, sometimes it doesn't.
sometimes the three windows work fine (they have for quite some time now), sometimes i boot and it's impossible to open more than one window.
sometimes they are even opened with 640x480, unable to change that resolution.

i don't know where to look, what to change, what i could do

i have attached a log where all i did was:
start the vm completely cold (open manager, open vm, boot up, log in), then shut down.
while i did this, initially three windows popped up, then 2 and 3 disappeared.

i hope someone can help me, it's pretty annoying

[Dan P]

I have a very similar problem: Windows 10 host, Ubuntu 18.04 guest.

Switched to 6.1.2 and specified "multiple screens" - 2. The first VM Screen appears fine... with the number '1' in the window title: "ubuntu 18.04 (Running) - Oracle VM VirtualBox : 1"

There is no second screen....

Version 6.1.3 and 6.1.4 have their own problems....