Sayyed Mohammad Al-Musawi, Sayyed Mohammad al-Musawi is originally from Iraq and heads up the World Ahlul Bayt Islamic League in London. Other than being involved in various humanitarian projects, he frequently responds to... Answered 1 year ago

Neither washing nose is obligatory in Wudhu nor washing mouth. Both of them are just recommended and not obligatory. Washing head or feet in Wudhu is wrong because you should wipe over them and not wash them.

If you are sure that your Wudhu was invalid, you need to perform it properly and re do the prayers which were done with wrong Wudhu.