Owners of the Apple TV 4K set-top box have taken to Apple’s forums, Twitter and Reddit to complain about certain shows no longer streaming in the Dolby Vision HDR format.

It’s unclear if this is an issue with Apple’s streaming service, a deliberate downgrade in terms of image quality on Apple’s end or a problem with the latest tvOS 13 update, but multiple reports worldwide in the past few weeks from subscribers to Apple TV+ indicate the problem affects new and existing episodes that previously used to stream in the Dolby Vision HDR format.

Specifically, the issue affects early episodes of “See,” “The Morning Show” and “For All Mankind” which have now reverted back to the static HDR or HDR10 format on television sets that officially support Dolby Vision. “The same goes for brand new episodes of these shows that were released today, despite the fact that they still carry the Dolby Vision HDR support label on the summary screens,” MacRumors observed.

It’s worth noting that the problem doesn’t currently seem to affect all shows on ‌Apple TV‌+ for at least some users. There are scattered reports that ‘The Elephant Mother’ documentary and Apple’s ‘Dickinson’ show still appear to be streaming in full Dolby Vision HDR, as do some kids shows like ‘Snoopy in Space.’

This issue shouldn’t be dismissed lightly as Dolby Vision is considered the highest-quality HDR format that’s widely available.

Compared to static HDR10 which works uniformly across content, Dolby Vision HDR use dynamic image metadata that enables Dolby Vision-capable TVs to adapt the extended color gamut and increased contrast range of HDR on a scene-by-scene and even frame-by-frame basis. Losing the DV HDR support can result in scenes that look too dark, appear like a negative image, or have an odd tint to them.

For what it’s worth, the problem appears to be limited to owners of the Apple TV 4K streaming box only when connected to a compatible 4K television set. We’ve yet to spot complaints from Apple TV+ subscribers who stream shows using the TV app on their Smart TV or Roku.

We’ll be sure to update this article if Apple officially comments on the streaming issue.