Affects Version/s: Minecraft 15w35e, Minecraft 15w37a
Fix Version/s: Minecraft 15w38a
This may be related to
MC-79995 but this specifically refers to wall banners and standing banners.
This may only exist when there is large amount of banners, therefore reproducing the bug would be time consuming,
My theory is that there is a maximum render amount. And until some banners become unloaded, the furthest banners will not load.
Here is a video demo of the bug