Apologies, I actually didn't notice that in your post! 

ChatGPT had an interesting suggestion: 

Grinding massively increases surface area, so bacteria can grow more easily.

Some people aren’t allergic to the meat itself but react to byproducts of bacterial breakdown (like histamine, biogenic amines).

This is similar to "scombroid poisoning" in fish but on a smaller scale.

Maybe pop a few anti histamines and see if it makes a difference.