While you should not need to download ride videos in Vieta (streaming works extremely well on most modern internet connections) you can still download ride videos in your chosen quality preference.
If you are having trouble downloading, it may be caused by the following issues.
Hard drive space: Ride video files can be quite large, especially in the highest 4K+ setting. Keeping enough free space on your device will resolve most downloading issues. As a general guide, the file size of an hour-long ride video will be around...
4GB in 1080p 10GB in 4K 30GB in 4K+
Internet connection: Ensure that your device has a stable and strong internet connection, especially for Apple TV. Try giving both your Vieta device and your home WiFi router a reboot (power off at wall for a minute, on again) to clear any potential router issues.
Switching between apps: While your rides should still download in the background, keeping Vieta open on the screen and not switching between different apps can aid stability. This is especially true with older or lower-powered devices.
Please ensure that your device is up-to-date with the latest iOS, tvOS or Windows system releases.