Alexa dont hear for the wakeword during her announcements

After testing the application some time, i've noticed the i cant trigger Alexa during her announcements. Thats a little problem because you cant stop her reading the news or cange the volume during playing radio. Everytime i have to restart the pi or press t in the console. Do you have an Idea how to fix this?
Thanks for your great support and an nice Friday evening!