I tried creating an example document based on your posted example with different kinds of emojis, and was able to import it correctly using mongoimport.
I assume you tried to import this using mongoimport. Could you try to update the MongoDB tools by downloading from MongoDB Database Tools download page and try again?
If this is still not working, please post:
- Your MongoDB version and your OS
- The output of
mongoimport --version
Best regards
Kevin