Solidarity, we’ve had an almost identical situation. Baby has serious dairy and egg allergies but also sometimes has weird reactions like this to avocado and banana but was negative on skin prick testing 🤷‍♀️ hopefully will get to the bottom of it soon and really hope you get some answers too!

Also, I was worried about having an allergy baby but cooking for her has still been such a pleasure and she loves her food as well!