HyperV on r7910 - seems guest OS does not complete its boot

I have an r7190 computer with 2 CPUs, 4 hard drives (about 2TB) and 120GB of Ram. I'm trying to replicate what I currently have running on a T3500 with 1 CPU and 24GB of RAM. (hopefully better and faster with the more processors and more RAM).

On the r7910...

I have upgraded the BIOS to the latest version on the Dell Website.

I have enabled virtualization in the BIOS in the only 1 place I found "virtualization"  

I'm running Windows Server 2016 (for legacy software reasons).

I've enabled the HyperV role in Server manager and I've created a guest Windows10 and a guest server 2016.

HyperV manager shows the Windows10 guest machine has booted and is running.  However,

1 . when I connect to the console of the Windows 10 guest, the HyperV logo is still present  (instead of Windows10 login prompt) and

2.  when I click the left most button on the tool bar to send ctrl-alt-del to the guest OS, I get a pop-up "could not send the keys to the virtual machine's keyboard device.'

3. when I "reset" the guest I get the blue "Recovery...your windows couldn't start properly..." 

I have not tried to reset the Server2016 guest OS, but I'm pretty sure it also does not complete boot.

I'm very much hoping there is a setting somewhere that I am overlooking that will make this work.

I'd appreciate any help I can get.