The Ancient Egyptian hieroglyphics, though present in the macOS 15.4.1 (can be seen in Eclipse, see the screenshot) are not properly rendered by the JavaFX "system" font.

Also, not rendered in Swing with either "Dialog" or "SansSerif" font.

Test string:
\ud80c\udd42\ud80c\udc79\ud80c\udc4b\ud80c\udc68
𓅂𓁹𓁋𓁨