Clear cookies & Cache on Firestick

Go to Settings > Applications > Managed applications > Click the specified app (HW Q, HW XC IPTV or any other) >Clear cache
Once you don that you will need to re login to the app with your login details.
In most cases, clearing the cache on your Fire TV Stick will fix problems like slow speeds and app crashes. However, you may need to clear app data, clear cookies, or even reset your Fire TV Stick to its factory settings if that doesn't do the trick.