Hi stop the puree but first hand smash then slowly do the transition. Encourage self feeding, cut banana in small pcs and offer, let him pick and eat.

If you have been giving purees till now and have suddenly switched to solid chunks, the baby will refuse as hez not habituated to the texture of solid food. U have to make the transition slowly. Switch from puree to mashed food first, then coarsely mashed, and finally food in the form we eat.