I emitted madhiy but didn’t wash it off immediately and forgot about it. Later, I made Wudu without using the toilet or washing it off and prayed. I remembered after praying that I never washed it off. Is my prayer valid or should I repeat it

There are opinions, al Imam Al-Nawawi said in al-Majmūʿ: Regarding the schools of the scholars concerning one who prayed while having impurity on him, but he either forgot it or was ignorant of it, we have mentioned that the more correct opinion in our school is that repetition (of the prayer) is obligatory. This was also the view of Abū Qilābah and Aḥmad. But the majority of the scholars held that repetition is not required.