Cross pollination

Probably not. Shallots and onions will cross as both Allium cepa but leek is Allium ampeloprasum and won't cross with onions. I doubt your ornamentals are the same species as your onions.

https://hudsonvalleyseed.com/blogs/blog/...ollination

I did notice a post from 2013 on another site, started by a guest called veggiechicken, but they have probably forgotten that by now.