Hi Denig,
Thank you for contacting Syncfusion support.
Currently, we do not have options to handle the event of the suggestions based on the items. As we have maintained popup separately from the SfTextBoxExt, we are not able to handle its events. So can you please share the requirement of using events of items in the drop down? Based on your update, we will proceed further on this.
Regards,
Keerthana J