When a collection embedded in an index (either through an @IndexedEmbedded or @Field) is modified, changes will not trigger reindexing of the holding entity if this collection is an AbstractPersistentCollection with org.hibernate.collection.internal.AbstractPersistentCollection.isOperationQueueEnabled() returning true.

The problem was only confirmed on 5.8, but since the cause was HSEARCH-782 Closed I expect it to be present in about all recent versions of Hibernate Search.

I will submit a PR with a test case demonstrating the issue, and a fix.