In ArticleType, the validation_groups are set to ['default'].
When i add constraints to my BlockInterface with groups: ['default'], it works.

In PageType no validation_groups are set, when i add constraints to my BlockInterface the work with groups "Default".

When i overwrite ArticleType and set validation_groups to ['Default'], validation does not work anymore for Article->content.
When i try setting it to any other value: Validation does not work.