Hibernate @ElementCollection size / null validation always fails

I'm trying to set up an element collection for my latest spring boot project but I am having issues with the validation.

I want to make sure there is at least one value in the set.

I have tried:

@Size(min = 1)
@NotEmpty
@NotNull

But every time the validation fails. Even if I try and save a set with one or more items in it.

Here is the current code of the property in my entity.

@ElementCollection(targetClass=Integer.class, fetch = FetchType.EAGER)
@CollectionTable(name="campaign_publisher", joinColumns=@JoinColumn(name="campaign_id"))
@Column(name="publisher_id", nullable = false)
private Set<Integer> publishers = new HashSet<>();

The strange thing is that I have created unit tests for this validation and they work fine. This was done by getting a validator from the validator factory. For example:

ValidatorFactory factory = Validation.buildDefaultValidatorFactory()
validator                = factory.getValidator()

...

Set<ConstraintViolation<Campaign>> constraintViolations = validator.validate(campaign)

But when I send the entity to CrudRepository to be saved thats when the validation fails.

Also if I remove the validation on this property and run an integration test the data is saved correctly.

If you need anymore info let me know and I will provide it.

Thanks for any help!