I hope someone out there has some insight and can help me solve this.
I've had my fit-pc3 for around 7 years, and it's been serving as the home's router/firewall, access point, file and media server... I've always used Ubuntu Server as it's the distribution I'm more comfortable with, and I kept updating it until one update made it stop seeing the 4 NICs in the face module. I rolled that update back and kept my server on... 14.04, I think (maybe 14.10, it was 14 something for sure) for years.
Fast forward to a couple of weeks back, and I decided to try and see if current Ubuntu played ball with the face modules' NICs. I used a Live USB of the 19.04 Desktop edition and, indeed, I could see the OS bringing the total of 5 NICs up. Encouraged by that, I took the plunge and installed 19.04 server edition. The text mode installer worked fine and, apparently, the install process completed successfully. However, upon update, I got no output.
I'm fairly certain the OS is actually booting UP, as I can see it getting an IP in the ISP's router (which forwards all traffic to the fit-pc, hence my statement that it is the router

Things I've tried:
- Booting again with the Live USB and modifying the Grub config to include nomodeset in the default boot.
- Mess with the UEFI/BIOS to enable and disable BIOS exclusive booting, UEFI exclusive booting and both enabled.
- Update the UEFI/BIOS to the latest version (freshly downloaded a few days ago), then repeat the previous step again.
- Make the installer boot USB using MBR and GPT, trying installing using both.
So far my results have varied between booting and no output, and not even booting.
Has anyone been able to install a recent Ubuntu on this computer and have it output text? I don't need or really want a desktop as this is used as a headless server most of the time, administered via SSH, so text only ouput is perfectly fine.
Otherwise, what recent distribution does work without much hassle? I'd prefer something Debian based as it's the environment I'm more used to and with which I feel more comfortable, but I'm willing to try other things. If need be, I'm willing to try a BSD... But before trying things I'd like to ask if anyone has had success with recent Ubuntu on this little gem

Thanks in advance!