GitHub Pages cannot find assets

I’ve just set up an automated github pages with github actions and the index.html loads fine but you get a 404 when trying to load files in the _assets folder.
For example: https://matcool.github.io/ works but https://matcool.github.io/_assets/index.f31d2c02.js does not (both are present in the correct branch of the repo)

After some searching I found this https://docs.github.com/en/enterprise/2.14/user/articles/files-that-start-with-an-underscore-are-missing
I ended up having to rename the folder from _assets to assets even though I had the .nojekyll file present