The FeatureHolder transformer is designed for this.
Stores incoming features until they have all arrived, and then releases them in their original order.
Use this transformer whenever you want to detain certain features until all input features have arrived. This ensures that no additional processing is performed until all features are released.
Connect the FeatureWriter Summary port and the Sorter 5 output port to a FeatureHolder. Then a tester to remove the "FeatureWriter Summary" feature. Then connect the passed port to the HtmlReportGenerator.

The FeatureHolder transformer is designed for this.
Stores incoming features until they have all arrived, and then releases them in their original order.
Use this transformer whenever you want to detain certain features until all input features have arrived. This ensures that no additional processing is performed until all features are released.
Connect the FeatureWriter Summary port and the Sorter 5 output port to a FeatureHolder. Then a tester to remove the "FeatureWriter Summary" feature. Then connect the passed port to the HtmlReportGenerator.

Thanks again @nielsgerrits, that did the trick :)