The getter is `getMode` while the setter is `setMdmMode`. https://github.com/hapifhir/hapi-fhir/blob/1b3edb4f303dd5678d613c1e3aa87e85576f50bb/hapi-fhir-server-mdm/src/main/java/ca/uhn/fhir/mdm/rules/config/MdmSettings.java#L177-L184 This breaks Kotlin 'synthetic property' interop with Java https://kotlinlang.org/docs/java-interop.html#getters-and-setters I will open a PR to rename the setter (as the getter is defined in the `IMdmSettings` interface)