Can you look in /logs and see if there are any errors? We’re merging hundreds of (S)CSS formatting changes across themes/plugins right now, so it’s possibly related to that
I see scss compilation errors (makes sense, the raw color_definitions.scss file is present in the container)
SCSS compilation error: Error: @use rules must be written before any other rules.
╷
151 │ @use "sass:color";
│ ^^^^^^^^^^^^^^^^^
╵
/var/www/discourse/color_definitions.scss 151:1 root stylesheet