Spyglass on the head, but appears at my hand using /replaceitem

Dear Mojang,

                       May I report about the bug I saw? I have something to show you. Recently when I type /replaceitem entity @a slot.armor.head 1 spyglass, somehow the spyglass appears at my hand instead on my head. Additionally, it still shows up on my hand even I don't have things to hold. It can override things that you can combine with other items. Speaking of visual bug, I hope you can fix it. I don't rush you. There are some bugs that need to be fixed, but you can count on me. Thank you!