Quarto visual and source highlights are different (non-default themes; VS code apps)

First noticed this issue in Positron but that's apparently due to an issue in the Quarto VS code extension itself and it also happens when using the visual editor in VS Code.

Describe the issue:

In quarto visual editor mode, the highlights change back to default theme instead of the currently active theme. This is independent of whatever theme was selected in YAML.

Example below: same document opened in visual mode (default highlights), source mode (rosé pine dawn no italics highlights) and the HTML file rendered in the viewer (ayu highlights).

Steps to reproduce the issue:

Using a non-default theme, create a .qmd document, write any code block like 1 + 1 = "bob" and switch to visual mode.

Expected or desired behavior:

Highlights should stay the same between visual and source mode.

System details:

Positron and OS details:

Positron Version: 2024.08.0 (Universal) build 48
Code - OSS Version: 1.91.0
Commit: ed616b36655fb24d116108bdd833f1321704315b
Date: 2024-08-19T04:26:51.868Z (1 wk ago)
Electron: 29.4.0
Chromium: 122.0.6261.156
Node.js: 20.9.0
V8: 12.2.281.27-electron.0
OS: Darwin x64 22.6.0

Interpreter details:

R 4.4.1

Start by reproducing the issue with a non-default theme in a .qmd document, switching between the visual and source modes in the VS Code extension. Compare the code-block highlights in both modes and in the rendered HTML viewer; done means visual and source mode retain the active theme's highlights.