Good to hear that you might be working out the issue. It does indeed seem to be an operating environment issue, not a HA issue.
This link is to Ubuntu Desktop, which is different to Ubuntu Server, hence why the question was asked. They are different versions of Ubuntu, and neither are called “Ubuntu Desktop Server”.
Bad idea. Don’t try and install HA in this way, especially with the issues you seem to be facing.
There is no installation type named Home Assistant Lite. Again, I would suggest you read up on the current installation methods. An excellent post HERE explains each method.
Do you any other old PC or laptop laying around you could try to install on? I would suggest it would be a good idea to try running on a dedicated machine if possible and see if you continue to face the same problems. It doesn’t have to be good/new/high-powered to run HA well. I’ve testing running HA OS with Proxmox and Supervised with Debian on a 10 year old Dell dual core laptop with 2gb RAM, which runs things adequately.