Mysql unable to store emoji in utf8mb4 collation
Paraphrasing https://stackoverflow.com/a/38363567/1766831 :

Question Marks (regular ones, not black diamonds) (Se?or for Señor):


The bytes to be stored are not encoded as utf8mb4. Fix this.
The column in the database is CHARACTER SET utf8mb4. Fix this.
Also, check that the connection during reading is UTF-8.  (That is, check phpmyadmin for utf8mb4.


Once ???? is stored, the Emoji is lost.  That is, the INSERT side has the problem.  The SELECT side may also have a problem.