Hi @Nick. Glad to see you have a little progress. We only officially support operating systems which are still receiving security updates. The age of the computer shouldn’t be the problem, but the OS on it might be.
I just wrote up a bunch of steps for another user. They might be helpful for you. They were having issues with RedHat working.
Could you take a look at the video I recorded and the steps as I perform them and maybe see how that works for you?
Find that post, video, and steps here: Admin Console not connecting to Edge Controller - #41 by TheLumberjack