Apologies Im asking on behalf of developer...
When emoji are posted in one IPhone, they are appearing as questions marks in a different IPhone.
How to rectify this?
Emoji appearing as question marks in chat across different devices
This is definitely NOT the forum to be asking that question! This forum is for developers who use XCode to write iPhone apps and Mac programs. That said, most likely it's because the iPhone with the question marks is running an earlier version of iOS that doesn't support the emojis you're trying to send.
I am ios developer and that issue come up that new imagin not appear right on feed. that show like what about that issue?