• Composite field now uses FormLayoutDefinition instead of PlainFormLayoutDefinition.
• propertyNameDecorator is missing: https://git.magnolia-cms.com/projects/PLATFORM/repos/ui/browse/magnolia-ui-framework/src/main/java/info/magnolia/ui/field/CompositeFieldDefinition.java
• idPropertyName is used only in JSON composite field: https://git.magnolia-cms.com/projects/ENTERPRISE/repos/rest-client-ui/browse/src/main/java/info/magnolia/rest/ui/field/JsonCompositeFieldDefinition.java

The composite field properties need to be updated.