14 old not eating

My toddler was never one of those babies that would eat whatever was on their plate, but lately she is not eating anything. She has lost weight this last month because of that. Has anyone experienced this? Did you get over it, found out why? I went to a feeding specialist and they said it is reflux and to have a procedure where they measure the ph in her stomach. I am certain she does not have reflux. She is fine nursing, for example. Problem is, I do not think i have a lot of milk, since she is not gaining any weight, despite nursing.

I see her more having a sensory issue with textures that are sticky. She accepts blueberries and bread for example (not big portions, small bites) , but not yogurt, cheese, eggs(I show them to her and wants to leave the table screaming).

Also, be it food that is on a spoon or finger food, she will take or bite just the tip of the spoon or food. 2-3 bites or spoonfuls and she is done. Does not want more.

It's also not teething since her not wanting to eat is from the beginning when we introduced solids. She would eat half of what we offered, but we accepted it, as she was gaining weight. It's now gotten worse. I am afraid whether it is sth serious, like a hormone deficiency or a syndrome, making her not feeling hungry or not knowing how to eat. I don't know. It's not normal to never feel hungry, or be tempted to eat.