My husband asks: Sometimes I left praying loud in loud prayers in some situations because I thought this could cause fitna or stress. I knew that leaving something for others is worse than riya but I didnt knew that it could apply in my situation. Do I have to repeat those prayers?

Ustadh AbdulAziz al-Haqqan

No, you do not repeat them, Imam Ibn Baz said reciting quietly in a loud prayer does not harm the prayer and there is no sujud al-sahw upon you, you have only left the better and the sunnah.