Sound Out of Sync for On Demand Content

I use an Amazon Fire Stick with the Xfinity Stream application to watch Showtime Content - in this case Dexter Resurrection specifically.

The sound is not synced with the video. Tried logging in/out, restarting the device, network connection is fine. It also seems to happen on other Showtime content and not on some other content (all played via on Demand through the app).

The same process on the cable box and mobile do not appear to have this issue.