Apple TV+ Lower resolution than expected

[Clarity3]

I have just purchased the Apple TV downloader with the expectation that 1080p would be the common resolution and 4K if available. Very much implied in the website details for this downloader. Having just downloaded my first film, it was offered at 862 x 466 as the highest resolution.

Am I expecting too much by thinking 1080 would be available and I should not trust the advertising blurb or have I missed a magic switch? If so, help will be appreciated.

[Germania]

have I missed a magic switch?

Nope, SD is default maximum for all releases - all quoted infos from here

Support to download H264/H265/Dolby Vision/HDR10+ video codec.
(480p for all of videos, part of videos up to 720p/1080p/4K)

Higher resolution (including FHD) are limited to popular, older titles ..
.. where the key for >SD at SF is known

With Apple, however, the clients only receive a key for SD and another key for audio.
SF therefore compares whether the appropriate key for >SD is stored in its database to enable dl >SD