To reproduce this:
1. Run any JavaFX application on macOS 11 (Big Sur)
2. The tray icon is a generic blue folder instead of the expected coffee cup icon
This only affects JavaFX applications. Swing apps are unaffected. See the attached screen shots on macOS 10.15 (Catalina) and 11 (Big Sur). The icon on the right is from a Swing app and the one on the left is a JavaFX app.
1. Run any JavaFX application on macOS 11 (Big Sur)
2. The tray icon is a generic blue folder instead of the expected coffee cup icon
This only affects JavaFX applications. Swing apps are unaffected. See the attached screen shots on macOS 10.15 (Catalina) and 11 (Big Sur). The icon on the right is from a Swing app and the one on the left is a JavaFX app.