My trigger was MSG (monosodium glutamate) but don't take my word for it. strong naturally occurring umamy taste can trigger for me too.

you should keep a journal of everything you eat, especially if you can take note of the ingredients.

For me 1 or 2 days after consumption triggers it, but staying away MSG helps in my case.

MSG sensitivity isn't taken seriously because it only really affect a tiny subset of the population and the food industry has interest in it not alarming the 99%.

I'm taking B2 which strengthens the blood brain barrier too.