My fix:
- I selected all the MetaSounds in the Content Browser and pressed “Save” in the right-click menu.
- It gave me an error message that my MetaSounds are somehow connected to a MetaSound asset I downloaded from FAB.
- I deleted that asset and restarted the Editor.
- I opened my MetaSounds and saw some “Registering MetaSound asset”, “Registration successfully completed”, " Document changed to 1.14v" windows popping up.
- This made all my MetaSounds get a * sign, so I resaved them all.