Exported MPR wrapped legacy components lose styles

[OlliTietavainenVaadin]

Description of the bug

When I have a V8 component with MPR's LegacyWrapper, I can use it without problems in a Flow view. If I try to use the same component in a React view via WebComponentExporter, the component appears and reacts to events as expected but doesn't have any styles.

Expected behavior

Legacy styles should be shown

Minimal reproducible example

https://github.com/vaadin/hackathon-24-4/tree/olli

Versions

• Vaadin / Flow version: 24.4.beta4
• Java version: 21
• OS version: Windows 11
• Browser version (if applicable): Chrome (latest)
• Application Server (if applicable): Spring Boot
• IDE (if applicable): IntelliJ Idea