There are two steps to fix this.
First edit phpMyAdmin/libraries/DatabaseInterface.class.php
Change:
if (PMA_MYSQL_INT_VERSION > 50503) {
$default_charset = 'utf8mb4';
$default_collation = 'utf8mb4_general_ci';
} else {
$default_charset = 'utf8';
$default_collation = 'utf8_general_ci';
}
To:
//if (PMA_MYSQL_INT_VERSION > 50503) {
// $default_charset = 'utf8mb4';
// $default_collation = 'utf8mb4_general_ci';
//} else {
$default_charset = 'utf8';
$default_collation = 'utf8_general_ci';
//}
Then delete this cookie from your browser "pma_collation_connection".
Or delete all Cookies.
Then restart your phpMyAdmin.
(It would be nice if phpMyAdmin allowed you to set the charset and collation per server in the config.inc.php)