You are having a reaction to nicotine salts. Juul started the trend of using nicotine-salts rather than nicotine. It has much less throat burn so you can get a higher dose, but it makes some people wheeze.
My guess would be too many terpenes (or extra added terpenes). A recent trend has been adding massive amounts of these volatiles to the mix (purchased in bulk from places like trueterpenes[0] - which has warnings all over it) to create "flavor profiles" or to more closely mimic the effects of smoking flower. These are the same as the toxic essential oils that people overdo. Some are far more potent than others and definitely can cause reactions (even in non-asthmatics).