Character encoding problem in backoffice only

Hello,

I have a problem with character encoding. In woocommerce back office, the apostrophes are replaced by : “ampersand sharp 039;”. The front office displays the apostrophes normaly.

I looked up the wp-config file and found that : define(‘DB_CHARSET’, ‘utf8’);
MySQL (5.5) is set up to “utf8 general ci”.

I read that the character set should now be set up to : “utf8mb4_unicode_ci”

Can anyone help me fix that?

Thanks for your help !