A problem with Intel HD Graphics 4000 on Xubuntu 20.04. Any ideas how to fix?

I have installed Xubuntu 20.04 on a 2013 Dell 7010 tower and I am struggling with the set up of the integrated Intel HD Graphics 4000.

Post installation the system would not start properly. The machine would boot OK in to Grub but at some point during Xubuntu's initialisation process the machine would stop and reboot itself.

After setting nomodeset in Grub I can now get the system to start. However, the system needs to have 2 monitors and this does not appear to work with nomodeset.

After some research I found this in the Arch wiki:

/etc/X11/xorg.conf.d/20-intel.conf

Section "Device"
  Identifier "Intel Graphics"
  Driver "intel"
EndSection

I added this, and rebooted, manually removing nomodeset in Grub, and the system booted with both monitors. Problem solved I thought, so I edited the Grub default configuration so the change would persist on reboot. On the first reboot it worked OK...but after the 3rd reboot it has stopped working and the original problem has returned...

The problem is not hardware related, this machine has Windows 10 installed on a separate HDD which works fine.

I feel I am close to getting this working but I am missing something...does anyone have any ideas?

Current output from inxi -Gx:

Graphics:
  Device-1: Intel Xeon E3-1200 v2/3rd Gen Core processor Graphics 
  vendor: Dell driver: N/A bus ID: 00:02.0 
  Display: x11 server: X.Org 1.20.13 driver: fbdev,intel 
  unloaded: modesetting,vesa resolution: 1920x1080~77Hz 
  OpenGL: renderer: llvmpipe (LLVM 12.0.0 256 bits) v: 4.5 Mesa 21.2.6 
  direct render: Yes