Do you recite the Qur’an in the same manner as you do in front of others as when you are alone?
If you led the salaah or someone asked you to recite the Qur’an would you recite beautifully?
Do you recite the same when you are praying alone at home in your optional prayers? If the answer is no then know you have a disease of the heart which is riyaa! (showing off)