I don’t know the facts but I would venture to say “he was learning at the Shabbos table” by himself, rather than sharing the beauty of his Torah with his son.
But in truth, history repeats itself.
Like the Sar HaTorah, Rav Shach ztzl, also Moshe Rabbeinu did not have sons that were learners. He taught the Torah to Ahron’s sons and THEY ere the ones that had the appreciation for it.