Janissaries were changed to not have a “ranged” tag so that they would no longer take bonus damage from horsemen and mangonels.
However, they still take 50% extra damage from mangonels.
Yes, I know they are supposed to take 50% extra damage from “ranged” attacks, but mangonels attack is NOT classified as “ranged” it is “siege”.
So at best there is a weird tooltip/terminology inconsistency, or this is a bug.