the command /kill @e[type=XPOrb] will not kill existing entities

When trying to kill XPOrbs using the command "/kill @e[type=XPOrb]", it says it found nothing. I have tried using /summon XPOrb, and that works. I have also tried "/kill @e[type=xporb]", but it produced the same result.

video: https://youtu.be/U0sduSpc5zA