Hello, excuse open topic but I found the solution of the problem, and would like to leave here to help others as well.
Well, when this happens it is because the database is not performing the correct reading utf8
To correct just open the wp-config.php file
and find the passage: DB_CHARSET
make sure that it is this way:
define ( ‘DB_CHARSET’, ‘utf8’);
Done, just save and probably the problem will be solved.
I have helped
Sincerely,
Tiago Taddeo