ObjectParameter<T> not working

Hi.

I want to create a custom VolumeComponent with a ScriptableObject reference as one of the parameters. On the surface this seems trivial with ObjectParameter<T> or an explicit wrapper MyTypeParameter from it.

However, when using ObjectParameter<T> directly, I get a NullReferenceException: Object reference not set to an instance of an object in VolumeManager on row 254, where it is trying to set default values.

// code

Using an explicit wrapper yields the same result or similar ones.
I cannot seem to find a workaround, any suggestions?