Hmm interesting I just received the lisle one from amazon and was about to return it since the caps don’t fit. Which adapter and cap did you use to get a tight seal?

Lisle 24680 Spill-Free Funnel https://www.amazon.com/dp/B00A6AS6LY?ref=ppx_pop_mob_ap_share

This is the one I got, I’m not sure if it’s the same one you have. I would love to use that one you linked but i don’t have compressed air which is a bummer.