Girls, what does this mean? Has anyone had this experience? We're on g…

Girls, what does this mean? Has anyone had this experience? We're on gavage. When the little one eats, she moves like a caterpillar, her breast releases milk then takes again. I transfer to another breast and she eats calmly for the first 2-3 and then acts the same way... there is enough milk, weight is gaining well. I transfer because earlier...I don't understand what's holding her back.