Emoji issue

For a while I haven’t been able to change all of my emojis skin tones anymore. For example, the girl with the crown emoji, if I want her to have brown hair rather than blonde, it won’t change. Or if I want the emoji to change race, I can’t do it. That goes for all of the hand emojis, etc. and I used to be able to change everything.. why is this? It’s so annoying..