--watch (and preview, server) discard custom separate style sheet after on live updates (style sheet is only considered correctly on first translation)

[N3bukadne7ar]

Version of Marp Tool

3.4.0

Operating System

Linux

Environment

marp-cli 3.4.0 marpit 3.0.0 npm 10.5.0 ubuntu 20.04

How to reproduce

1. Unpack attached minimal example
2. Start marp cli in preview mode with marp --html --preview --theme-set style/ -- presentation.md
3. --> The slides are initially rendered with the correct custom style (Heading in Red)
4. Make a change to presentation.md
5. --> The preview window does not immediately update (!). This is unexpected.
6. Refresh the preview window with F5
7. --> The custom style is discarded, heading rendered in black (!). This is unexpected.

Expected behavior

Custom style always loaded correctly

Actual behavior

Custom stylesheet seemingly ignored for any updates in "preview", "watch" and "server" mode.

Additional information

minimal.zip

[N3bukadne7ar]

Some additional info:

• As mentioned, I have also seen this behavior in the --watch and --server modes.
• There is no issue with style overrides done directly in the mardown file. E.g. I can change styles in the frontmatter or with a html