Can't Place Banners

Your username: Bedding
In which minigame/server does the bug occur: Creative 1, 2, 3
Detailed description of bug:
I haven't been able to place banners for about 2 months now. 2 months ago, i was trying to make an illuminati sign (as you do), only to find out i couldn't place banners, they just disappeared in my inventory. I brush it off as a bad day and move on.

But now, i try to make some decoration for a building only to find the same thing, i cant place banners.
They just disappear in my inventory. If it helps, the banners i place are +NBT (duplicated).

Thank you!

 

I don't think you can place duplicated banners, I'm not sure why. I think it happens to everyone.

 

It never used to happen before

 

I'm sure it did happen before.
I can remember not placing banners by duplication in the past.

 

Duplicated items are no longer allowed in the inventory, from what I can recall.

 

Okay. Locking.