Is it permissible for a man to remain married to a woman after he later discovered that he had suckled a number of fulfilling sucklings from her maternal grandmother?

If the man has suckled five known feedings within two years from his wife's maternal grandmother, then he is a maternal uncle to his wife through suckling. He must separate from her immediately, and his children are attributed to him and inherit from him, because his intercourse with their mother was seemingly permissible.