15 months old toddler refusing to drink milk at night

Hi Mummies, My boy is turning 15 months soon and from past 2 days he is refusing to drink milk before going to bed. Is this normal ? Till now he used to drink 120 months formula before going to bed. I usually give him milk after dinner. But suddenly now he refuses to drink milk. Any mummies faced this? What shall I do ? Is this normal growth path for toddlers ? #firstmom #advice