This is a common misconception.

I begat my children in the past before reaching high initiation. Today I am completely forbidden to engender children again. - Samael Aun Weor, Secret Notes of a Guru

In other words, he had children without maithuna, before he achieved any Initiation of Major Mysteries. Once he correctly understood the path and starting practicing, he began to achieve them - or better said, recapitulate them, because he had already had them prior to falling in prior lives.

See here: https://glorian.org/books/secret-notes-of-a-guru/march-2-1952