I don’t know why you didn’t fix this.
You should not use load_textdomain directly. Instead, you should use load_plugin_textdomain here.
load_plugin_textdomain( 'acf', false, dirname( plugin_basename( __FILE__ ) ) . '/lang' );
load_plugin_textdomain will make customized language file easily. I can just put my language file into wp-content/languages/plugins.
Please fix it.
