Maybe debugging to a file might work around the problem:
define( 'WP_DEBUG', true );
define( 'WP_DEBUG_DISPLAY', false ); // não mostrar na tela
define( 'WP_DEBUG_LOG', true ); // escrever debug em um arquivo
@ini_set('display_errors',0);
With the constant WP_DEBUG_LOG
enabled, the debug will be generated in the /wp-content/debug.log
file. This constant is used to see Ajax or wp-cron errors that are not displayed on the screen during the execution of the site.
Some time ago, I did a plugin to view that file directly in the WordPress backend.
If even using the direct debug to a file your site still does not work because of these constants, then you should look in your server's error logs to see if there is any hint of what is really happening. This solution is just an alternative to get around the real error (conflict WP_DEGUB with your server), I did a quick search and found nothing related.