The current steps I have tried to mitigate this:
- Reinstalling the Bartik theme using
composer - Cleared cache
drush cache:rebuild - Turned off pre-processing in my Settings
- Assured that there's no errors in Drupal logs with file permissions specifically
- Tried using a macOS environment and a Windows environment
I am currently using a Docker instance to run Drupal (expanded on docker4drupal) however when trying to run it locally the HTML doesn't seem to render.
Some of the theme blocks seems to render (I can see some bartik theme mentions) however the surrounding HTML is not rendering at all. So none of the CSS or JS is even being embedded because the entire page is missing the <HTML> <head> and <body> tags.
The theme is a default theme to Drupal, it is deprecated now but did previously work after the Drupal 9 upgrade. I've also tried changing themes to classy and seven which are also default themes for Drupal and still the same issue which makes me think it's not a theme-related problem.