(Pocket-lint) - Eagle-eyed Amazon Prime Video users may have noticed that bitrates have risen to pre-lockdown quality recently, with Ultra HD shows and films restored to their former glory.

The voluntary bandwidth restrictions have eased in Europe and beyond, now that ISPs have shown to cope with increased demand.

However, some have also noticed a strange anomoly with the streaming service - support for Dolby Vision and Atmos has disappeared, with shows such as Jack Ryan now only available in HDR10 (or HDR10+ if you have a compatible TV) and 5.1.

And bought movies that would usually carry either or both Dolby technologies are now downgraded.

That has lead to a couple of theories being posted online, but Pocket-lint can reveal that neither are true. There was a suggestion that Amazon withdrew from its licensing agreement with Dolby to save money, while another possible reason put forward was that the service was continuing to limit bandwidth use, even with the return of higher resolutions.

But, the real reason is actually more simple than either of those - it seems to have been a fault which will soon be fixed.

While we can't say much more than that, we understand that Dolby Vision and Dolby Atmos will return to Amazon Prime Video soon.

That's great news, especially for Atmos fans and owners of older LG TVs without HDR10+ support.

So, keep an eye out for Jack Ryan, Bosche, Suspiria and any other programming that comes with Vision, Atmos or both.

We'll also update you if and when we find out more.

Writing by Rik Henderson.