[Question] Broken absolute_url

[COM8]

I'm working on my own web page based on your theme (https://github.com/UWPX/uwpx.github.io).
Locally everything works fine, but as soon as I publish it on GitHub links start to break.
For example:

1. I'm navigating to https://uwpx.github.io => the index page loads just fine
2. I click on "Blog" => it navigates me to https://uwpx.github.io/uwpx.github.io/blog/
3. I click "About" => it navigates me to https://uwpx.github.io/uwpx.github.io/blog/uwpx.github.io/about/

It looks like it's not grabbing the correct absolute_url.

Link to my _config.yml.
Link to my nav.html.