Spring boot, sub entity, records automatically deleted without save and update

Question

Issue: Records are deleting automatically from sub entity without firing any save/update statement. Need to prevent that deletion.

Below is entity:

@Entity
@Table(name="siteuser")
public class User implements UserDetails {

    @ManyToMany(fetch = FetchType.LAZY, cascade = CascadeType.ALL)
    @JoinTable(name = "siteuser_subcategory",
    joinColumns = {@JoinColumn(name = "userId") },
    inverseJoinColumns = { @JoinColumn(name = "subCategoryId") })
    @JsonIgnore
    private List<SubCategory> subcategoryList = new ArrayList<SubCategory>();

}

Here in cascade I tried all possible options DETACH,MERGE,PERSIST,REFRESH,REMOVE but no solution.

Also there is no any physical class entity for table 'siteuser_subcategory'. That table managed by only this above code.

I tried many ways to solve this issue as explained in this link Why does Hibernate try to delete when I try to update/insert?

Please guide for better solutions or anyway by try it.

Thank you in advance.