When you use getType with any of the new 1.15 items, it returns AIR instead of the real item Material.

Here I attach a plugin I made so you can test it with PlayerInteractEvent (just interact with any new item). Basicly my plugin sends the player who interacts a message with e.getItem.toString and e.getItem.getType.toString. When you use getItem, your message sent says it is a HONEY_COMB (for example), but when you getType of it it says it is AIR. (If you see the screenshots you will understand it better)

Source code: https://pastebin.com/9xaWLurR