Emojis in iPad Emoji Keyboard Sometimes Disappear. Only a blank gray box is displayed.

iPad Mini 2 Retina

iOS 8.1.2

This seems to only affect iMessage.

The Emoji Keyboard is enabled. (Not an app. The default Emoji Keyboard that comes with iPad)

I can touch the smiley face between the 123 & mic symbol. Usually this works fine, but sometimes I just get a gray box, no emojis display. I cycle through all the groupings on the bottom, all show a blank gray box, no emojis. If I double tap the Recently Used, they often come back, but not the others. Maybe recently used are stored locally, not loaded from a server? This problem usually persists for hours or a day, then resolves on its own. I don't know why this happens, or how it fixes itself. Exiting iMessage and reopening has no effect. Deleting conversations has no effect. This has happened ever since I first got this iPad Mini. There has already been 2 iOS updates since purchase, problem still happens. It happened last night and continued until a few minutes ago. Now it's normal again. No idea why.

Now for the really weird part: Sometimes even when I can't see any emojis on the keyboard, if I touch the screen randomly, an emoji will appear in my text message. As if the emojis are there, functioning, but they are not displayed on the keyboard, so I have no idea what I'm touching. ???

Has anyone else experienced this? Anyone know how to fix this permanently?