on my brand new MacBook
- If you just got a new Mac, and the download is older and transferred, then you may need to delete and re-download content, as the download is valid only for a specific Apple ID account and device combination.
- If you just got a new Mac, then verify that you have authorized this Mac. Only authorized computers can play downloaded content with Apple DRM.
Apple uses HLS video now for all downloads of Apple video services on current OS versions. Downloads from Apple’s servers in other formats do not seem to be an option at this time.
m4v/mp4/mov was very useful for Home Sharing, but that still is no option for Apple video services (buy/subscription) on modern Macs at this time (but in-app AirPlay works as alternative). Playback in HLS video format (movpkg) is of course very much supported on the device to which the media file was downloaded.
If your issue is about Home Sharing, then please let Apple know about your wish for HLS support through Home Sharing. More feedback may help Apple prioritize this. Product Feedback - Apple:
Feedback - macOS - Apple
or Feedback - Apple TV App - Apple