My Memoji is wearing Black Face! Some are white some are black...

Black face on my Memoji?? My iPhone has turned some of my Memojis black. I have tried to get the correct skin tone for all of my Memojis but it still has some of them white and some black. I know how to change the skin tones but it doesn’t affect the black ones. I am on the most up to date OS and I am not sure what to do. Has anyone else had this happen?