This is normal.
When my daughter was 4.5 mths old, we have started her on semi-solid food and added 2 scoops of cereal in her formula (only day and night feeds) and then now at 10 months old, she is only taking 3 times milk - 210ml in the morning and 180ml in the other 2 feeds.
It didn't worry me as I know my girl is more keen in adults food and we are slowly introducing her finger food such as french fries, rusks, cupcakes, bread (of all kinds), baby carrots, tomatoes, fish, poultry, cheese and porridge.
My girl has acid reflux and was on Similac Total Comfort for a couple of months. I switched to another brand of formula after observing that she has grew out of acid reflux and lactose intolerance.
At 7 months, perhaps you could try other food with your girl. Babies are like adults, they get bored too after eating the same type of food/milk continously.
I like to explore and change/update the food menu for my girl and see her enjoying her meals.