Check the settings.json file: {Project_Directory}/theme/settings.json
Look for the "cssFiles" property and for each css path, add a forward slash, i.e.
BEFORE
"cssFiles": [
"styles/web/css/main.css"
]
AFTER
"cssFiles": [
"/styles/web/css/main.css"
]
The rendering is still a bit odd, but in my case it did solve issues where I could not even see anything on my screenshots. This is one of the answers support gave me and it did improve my screenshots.
I solved it differently. In index.html
I replaced the macro with explicit line
<link rel="stylesheet" href="/theme.compiled.css?{{cachebust}}">