Not drinking much FM

My baby girl is about 10.5 months (she’s 2 months premature so about 9 months) and somehow refuse to drink much of her formula milk. Everytime we wanna feed her she’s like struggling or rolling away very fast. She’s eating her porridge twice a day but when it comes to drinking milk. It seems that she’s drinking lesser and lesser per day. I’m very worried she’s not getting enough nutrition and milk. Is it common?😫😫