Unity Hub sign in window blank, no "solutions" provided so far have helped.

I cannot verify my license for Unity, as Unity Hub will not let me sign in. I've tried updating to latest version, uninstalling Unity Hub and/or Unity, running as administrator, and even installing older versions.

I've also tried about 5 different methods of downloading Unity that are supposed to bypass the hub (by signing in directly in Unity) but all these methods just launch Unity Hub to verify my license, and then I have the same problem. Or if Hub is not installed, it links me to the install page.

I'm trying to complete an online course on using Unity/Blender to make a game, and so far I have only managed to do the Blender half.

Also, I doubt this is relevant, but I have used Unity on this PC before and it worked fine, until it logged me out for no reason. Unsure if a recent update has caused the bug, or if I did something wrong.