Sophos UTM Installation - ALT+F2 Console switches to black screen

Good evening!

Im struggling with a UTM 9.7 Installation for a UTM Home Setup.

I have an old SwyxExpress X20 Desktop PC with two Intel NICs. For Installation i use an USB Stick.

So, i boot from the USB Stick, works fine. Installation went into the error, that install.tar was not found.

I saw several posts about the workaround to mount the USB device before continuing the Installation. Here comes the problem.

When i press ALT+F2 to switch to the console, i see the console, start typing the commands and suddenly i get a black screen.

Sometimes it comes immediatly, sometimes after 4-5 seconds. 

I saw a post about HDMI Issues, so i tried it with my monitor connecting via VGA, but i get the same problems.

Does anyone expierenced this or has further information, where i can look?

Thanks! 

Regards, Chris!