Try to Hyde veggies or make different presentation of food. You can ask your partner to feed him sometimes at times this tip helps a lot. I usually ask my mother in-law to feed him and at that time i don't make any interference.
Try this and let me know 🤗

Try and observe what kind of food he loves having and try and play around that taste. It might be just a phase where they reject foods. So don't worry try after some days.

Hey the taste keeps changing and you should keep trying new dishes... Give fruits and juices.. sharing a few articles...
Give enough water...add papaya in dal or khichdi..