I think I'm running into the same issue, Windows 11 Firefox 109.0.1. The "ridge" of the reflection effect is stuck to the lower ~10% of the button, and completely dark, and the gold looks distinctly green.
Left is firefox, right is Edge (appearing, I presume, as intended)
Left is firefox, right is Edge (appearing, I presume, as intended)
[0] https://snipboard.io/AVU6zh.jpg