Issues regarding phpMyAdmin - character set
MySQL did not have utf8mb4 until version 5.5.3; are both versions newer than that?

Is the exported file a text file?  If so, look in it for utf8 and see if it says utf8 or utf8mb4.

Did you use any "character set" argument on mysqldump when exporting?  What about on importing?  For mysql and phpmyadmin it needs to be utf8mb4.  For the rest of the world, UTF-8 or maybe UTF8.