Browser: Edge 120
OS: macOS
URL: https://calysm.com/
Video: Short screen recording that illustrates this issue (free tool: jam.dev)
The custom css in the editor will apply the css changes you make to it in the builder, but when you see the live site, those stylings don’t actually take effect.
I added white-space: nowrap; to a heading element in the nav bar and it works in the editor.
However, when looking at the live page, the line breaks and there’s no evidence of the white-space attribute being added in the styles for it.