Lazy properties in embeddables/composites are not currently supported for embeddables due HHH-10480 Reopened .

The fix for HHH-12592 Closed will call the owning entity BytecodeEnhancementMetadata#isAttributeLoaded for a collection contained within an embeddable, using a property name that is qualified by the embeddable (e.g., grouping.things). The method simply returns false in this case, because there is no lazy property with this (qualified) name.

Depending on how HHH-10480 Reopened is fixed, Hibernate may need to be changed to call BytecodeEnhancementMetadata#isAttributeLoaded for the embeddable (not the entity) with an unqualified property name.

I made a small change to the fix for HHH-12592 Closed so that Hibernate does not bother calling BytecodeEnhancementMetadata#isAttributeLoaded if the collection is in an embeddable.
I will also mention this code needs to be revisited when HHH-10480 Reopened is fixed.

I also added a couple of tests involving lazy collections in embeddables that shows that things work properly currently, before HHH-10480 Reopened is fixed.