When minecarts are shot with a bow, the dropped item will be named "entity.minecartRideable.name", appearing in italic as with a custom name from an anvil. This occurs on Realms, so it is not a plugin bug. OptiFine is installed, but this shouldn't affect it. I have included the output log for going on to my Realm, placing a minecart, shooting it in survival, and then quitting.