Seen App. Voice & Video call issues

I dont know whats going on with this app. Its doing half& half. When I open the app & click on Seen Test. If I click on Video call, I can see & hear the lady give instruction on how to do video call. Then when I click on Voice call, I cant hear instruction on how to use voice calling, then sometimes vice versa. Can this issue be fixed? I really would like to use this app.

Lady T Wyatt about Seen - Video calls for Facebook