Sony promised way back in January 2017 that it would eventually roll out an update to its high-end 4K and OLED TVs that would enable them to be compatible with Dolby Vision content.

That update is now rolling out a year on, but there's one problem, it doesn't work with Dolby Vision sources over HDMI or USB. That means Dolby Vision sources such as Oppo's UDP-203 and UDP-205 Blu-ray players and the Apple TV aren't currently supported.

Rather ironically, Sony unveiled its first 4K Blu-ray player to support Dolby Vision at CES 2018, but as it hasn't been released just yet, it's not clear if it will work or not.

The only Dolby Vision sources that do work with the update are built-in apps on Sony TVs, such as Netflix.

Sony is aware of the issue, mainly thanks to the comments from angry Sony TV owners and Forbes writer John Archer has heard whisperings that Sony may take away the limited support while it tries to find a fix to the problem.

Sony's high-end TVs include the A1 OLED, ZD9, X940E and X930E models, and it's believed they all have the potential to support Dolby Vision over HDMI, making the whole situation all the more peculiar.

Archer has previously discovered that Dolby Vision sources over HDMI can occasionally introduce elevated black levels. Dolby admitted it was the culprit of the issue and quickly found a fix, but it was down to TV manufacturers to implement it as part of their own firmware updates. There's a chance Sony has still yet to roll this part of the firmware update out to TV owners, which could explain the limited support for built-in apps.

Archer adds that the most likely explanation for Sony TVs not working with Dolby Vision sources over HDMI is that the TV update has introduced a new 'profile' version of DV that is incompatible with other equipment. A possible fix is to ensure Dolby Vision sources have the latest software installed, although this isn't confirmed to be a genuine solution.

It's an annoying situation for Sony TV owners, as we know just how good Dolby Vision content can look, and we feel as many people should experience it as possible. We're hoping Sony can arrange a fix as soon as possible.