It's not a riddle- it's a Befeirusha Tur

How do we know that the Rambam ate Gebrokts on Pesach?

Mefurash in טור

The טור (O.Ch. 475) writes that the Rambam & R Amrom Gaon both hold that the Matzoh at the Seder needs to be dipped in the Charoses.

According to Harav Hagaon R.Y.S Elyashiv zt"l, one who has the Minhag of not eating Gebrokts may change his Minhag to eating Gebrokts.

It is preferable to make התרת נדרים but not necessary.
One may rely on the התרת נדרים made on Erev Rosh Hashana.

Reb Elyashiv holds that the original Chumra of Gebrokts started when Matzohs were thick.

Today that we have thin Matzos there is no chance of having
unbaked flour.