In my environment, I was able to evade all phenomenon by adding the following setting to .htaccess.
php_flag output_buffering Off
php_value output_handler none
php_value default_charset UTF-8
php_value mbstring.language japanese
php_flag mbstring.encoding_translation On
php_value mbstring.http_input auto
php_value mbstring.http_output UTF-8
php_value mbstring.internal_encoding UTF-8
php_value mbstring.substitute_character none