Sky F1 UHD / HDR feed stutter

[Tarrantino]

So I called Panasonic yesterday. Went to them with all the details we have here. Plus the everything I have tried and tested. 

They've now taken this to relevant department and factory. 

So we'll see what happens now. 

[jezzer42]

An Update,

Having uploaded a couple of videos to Panasonic, through their web-chat over the last couple of days, that clearly show the problem, I have subsequently had an e-mail from them this afternoon (10/4/25) letting me know that the case has now been refered to the factory for further investigation. 

Hopefully we will get a resolution soon.

[jezzer42]

Sorry didn't see your message until I posted my update. From what panasonic have said to both of us, I feel we may be getting somewhere.

[Tarrantino]

Don't be sorry. It's great they've said the same thing. 

[AlexDavison]

Thanks both, much appreciated.

I too will raise a case with Panasonic in the hope it gains some traction with them. 

[jezzer42]

Quick update,

Spoke with Panasonic this morning and was told that the issue was still being investigated by the factory. No indication of how long this might take but was assured that I would be informed as soon as a fix is available.

[Tarrantino]

I noticed this morning there's an update on the Panasonic website for the TVs. However seems they're still working on it. 

I was only wondering if the other day about contacting Panasonic soon. Glad they're still working on it. 

[lettice]

@jezzer42 

i took this thread into our Superusers closed forum to see if we can call in any Sky help, to work along with Panasonic.

It has been requested from Sky, they may be able to help further.

Do you have any kind of reference information or contact info that you are dealing with at Panasonic, re the issues that Sky can then engage with Panasonic directly on.

We will be happy to forward that onto Sky.

If you wish, you can PM the details and will pass on, rather than presenting the information in a post here.

[jezzer42]

Hi, Replied by PM.

[lettice]

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@jezzer42 wrote:

Hi, Replied by PM.

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Thanks have passed onto Sky who are looking around the issue.

[lettice]

For some further help, could some of you having the issue read the following, try and report the results here;

A test to check other HLG content and see if that buffers in the same way.

1) Try Sky Q iPlayer app and see how that performs  with HDR content.

2) Try the native app of iPlayer on the Panasonic TV for HDR (HLG) content

3) If you have a 3rd party hdmi stick with iPlayer, try this test also for HDR content.

4)  Is it all HLG content on the Q box that is affected, ie movies, or other sports events etc.,. or just the f1?

[jezzer42]

Hi Lettice.

Firstly let me answer your questions -

1 The iPlayer app on my Sky Q Box only plays in HD not UHD which works perfectly.
2 The native iPlayer app on the TV works perfectly No issues as do the native Netflix and Prime apps. HDR content looks fantastic.
3 I have a Sony 4K UHD HDR Blu-Ray player that plays perfectly on the TV (on any HDMI port) but the HDR mode is either HDR10 or Dolby Vision, not HLG.
4 It's all HLG HDR content from the Sky Q box - Sky Movies, Sky Atlantic, Netflix or Prime. Non HDR content plays perfectly

I am not the thread originator, I came across the thread when the originator and another community member mentioned that they also had Panasonic Z95A and Z90A OLED TV's (they use the same firmware) and were having issues with HDR content.

Interestingly if I download an HDR movie to my Sky Q box and repeatedly play the same two minute section over and over again the TV will stutter three or four times during that two minutes but the stutter doesn't occur in the same place each time, in fact rarely in the same place, but it will stutter three or four times nonetheless. I think we can therefore rule out data corruption in the recording.
The audio soundtrack is never interrupted, so its not a buffering issue as HDMI carries Audio and Video in one data stream.
Occasionally during a stutter the picture appears to dim slightly, as though the HDR data has been lost, and then brighten again as the video playback resumes. This isn't always visible, but is on one of the videos I have sent to Panasonic UK. This was easily discernible when playing back the recorded video in slow motion in VLC player on my laptop.

A quick timeline

1 New TV purchased in December 2024 (Replacing a Panasonic GZ950 HDR OLED TV) and all Sky Q HDR Content plays perfectly Firmware version updated to RS8112/2463 during initial setup.
2 Sometime in Mid February I noticed that programs in HDR were occasionally stuttering whether from Sky Movies, Sky Atlantic or the Netflix or Prime Apps. TV had automatically updated to version RS8130/3200 on or around 6th February 2025.
3 Initially spoke to the retailer and then to Panasonic UK who arranged to have the "main board" in the TV replaced which they did.
4 TV started up WITHOUT connecting to a network and initial setup completed TV Firmware version was now RS8112/2363 from June 2024.
5 TV Worked perfectly with Sky Q box, no issues at all, any HDR content played perfectly, apps, movies, Atlantic, all ok.
6 Used the TV like this for a few days before speaking to the retailer again, who advised plugging the network back in.
7 Plug the network in, switch on, and the TV almost immediately updated to version RS8130/3200 (6th Feb 2025) the STUTTER WAS BACK exactly as before.
8 Spoke to Panasonic UK again who opened a case and asked me to upload some videos of the issue, which I have.
9 Spoke to Panasonic UK on 29th April for an update and was told the issue is still being worked on and they would contact me when a fix was available.
10 A new firmware version RS8138/2921 (29th April 25) is listed on their website which may fix this issue. But I, like others on the AVForums Z95A owners thread, have not been able to apply this update.

Diagnostic steps taken -
1 Two new 48Gb certified HDMI cables purchased one from Audioquest, which wasn't cheap, no improvement to the issue.
2 My Sky Q Box works perfectly with all HDR content on my Panasonic GZ950 OLED TV.
3 My Sky Q Box works perfectly with all HDR content on my sons Samsung 4K HDR TV.
4 MY Sons Sky Q Box displays the same stuttering issues on my Panasonic Z95A TV.
5 MY Sons Sky Q Box works perfectly on my Panasonic GZ950 OLED TV, and on his own Samsung HDR TV.
6 Switching the TV HDMI Mode to Mode 1, all content now plays perfectly but of course no longer in HDR.
7 Switching the TV HDR Mode off, all content now plays perfectly but of course no longer in HDR.
8 Switching the Sky Q Box manually into 8bit 2160p I can no longer play any HDR content to the TV but all 4K UHD content plays perfectly.
9 Leaving the Sky Q Box in 10bit 2160p and only downloading NON HDR UHD content works perfectly. Apps are obviously still a problem as they automatically play in HDR when the Sky Q box is in 10Bit 2160p mode.

Summary -
I think we can rule out HDMI cables and Sky Q boxes as the problem only occurs when playing through the Panasonic Z95A TV.
The problem only started on the TV after a firmware update, although to be fair I don't know whether it was the January 25 update or the February 25 update. When I had the main board replaced it was initially on the June 24 version of the firmware (and worked perfectly) and that updated in one jump to the February 25 version (where the stutter was back)

Hope this helps, if you need any further information, please get back to me.

regards

[BenJoBanjo]

@jezzer42 

Sounds to me like it's a specific issue with HLG at 50Hz from an HDMI source. 

I have a Panasonic JZ1000 OLED and haven't had any trouble. When I had Q I could download the UHD HDR version of on demand content and it played fine. The HDMI socket was set to mode2. I used the same when I switched to Sky Stream and again no issues. 

Does your TV have any sort of Game Mode or ALLM (Auto Low Latency Mode) and/or VRR (Variable Refresh Rate) in the settings? It might be worthwhile turning these on and seeing if it makes any difference.  

[jezzer42]

Hi,

Yes, I think you are correct. That's the conclusion I had come to, it's specifically HLG content over HDMI. HDR10 content from my Blu-Ray player works perfectly. And as I said in my earlier post my Sky Q box works perfectly with my GZ950 which is in another room, which is about 3 years older than your JZ1000. The main difference between the GZ950 and JZ1000 and the Z95A is operating system. The GZ and JZ use Panasonics own OS, Whereas the Z95A is a fire TV, and that's not necessarily a step forward.

With regards to HDMI ports, two ports are HDMI 2.1 and support VRR and ALLM the other two ports do not support these modes but are 4K HDR up to 120Hz. Turning these modes off or on makes no difference whatsoever, additionally it doesn't matter which port I use I get exactly the same issue and the only two settings that I can change, on the TV, that make any difference to the stutter both switch off HDR!  Which kind of defeats the object of an HDR TV.

[BenJoBanjo]

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@jezzer42 wrote:

The GZ and JZ use Panasonics own OS, Whereas the Z95A is a fire TV, and that's not necessarily a step forward.

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100% agree. FireTV OS is horrible. The older OS on the GZ and JZ series is much better.

If you have any streaming device knocking around which has the UHD/HDR capable version of the iPlayer app on it then it would be worthwhile giving it a go to see if the same thing happens with 50Hz HLG UHD content from it. The iPlayer app is one of the few apps which does (correctly) force 50Hz for all its output and frame rate matches on most platforms. The 4K Firestick for example is stuck on 60Hz for most apps but the iPlayer app does switch to 50Hz on it. 

Hope you (and Panasonic!) manage to get a fix sorted for it.