20months LO not drinking milk after dinner

My 20months LO suddenly don’t want to drink milk on his own by bottle or cup… wana be spoon feed… usually he drinks b4 he sleeps at 8.30pm n last time at 11pm until next morning… but these few days he doesn’t want anymore… my mom is worried that he is hungry if he doesn’t want milk the whole night as his last food intake is about 6pm which is his dinner. Any mommies face same issue? How to solve this issue?