The children of Korah died not God being pleased to spare them, because they disowned their father's act, and separated themselves from his tent and company. Hence the sons of Korah are mentioned 1 Chronicles 6:22; 1 Chronicles 6:38, and often in the book of Psalms.
Related Commentaries of Numbers 26:11
Numbers 26:11
11 Notwithstanding the children of Korah died not.