In DeployBeanPropertyLists.getMany(Mode), ManyToMany associations are correctly added to the list of associations to cascade on save, regardless of whether the association is configured to cascade or not, as indicated by the comment in that method.

However, when it comes to using this list:

if (saveMany.getMany().isManyToMany()) {
// save the beans that are in the manyToMany
if (saveMany.isCascade()) {
// Need explicit Cascade to save the beans on other side
saveAssocManyDetails(saveMany, false, saveMany.isUpdateNullProperties());
// for ManyToMany save the 'relationship' via inserts/deletes
// into/from the intersection table
saveAssocManyIntersection(saveMany, saveMany.isDeleteMissingChildren());
}
} else {
...

The association is only saved if cascade is configured. the saveAssocManyIntersection call should be outside of that if statement.