I can confirm the issue with the clip as described by @TTTGary and welcome to the forums too btw.
It does play correctly on any Windows x86 platform.
If I turn off hardware acceleration then there is some improvement but not enough to be happy with.
I’m guessing that TVHeadend us being used to configure recordings?
If so, then I wonder if, in the short term at least, it is worth changing the stream profile for recording to another option to see if the output is more acceptable.
I regularly record Match of the Day/2 in HD using the matroska profile and have not to date encountered the same issue myself with any release and I tend to use every nightly coming out.
It is good that something has been identified before, with samples having being shared and discussion taken place and patience is required to allow things to happen in the background.
The fact that so far, only 2 people have reported the issue(that I can see) since early May does seem to indicate that this is not a wide scale issue and therefore, quite understandably, would not be top of any fix list and from my experience, when there is a solution to an issue, you can bet that the team will publicise it. Until then, if there is no solution and the issue has been identified, any open forum discussion would not realistically have any benefit for anybody, save for any new reports that the team are not already aware of.
@Tim_Taylor is correct to remind us that a lot of work is done in free time and for free and so never a bad thing to take a little step back from what might at times feel a little frustrated to know just how much benefit we get from CE and all that goes into it.
If only the people that we purchase the boxes and SBC’s from put in the same amount of effort in as the CE team does, particularly when vendors are not doing things for free but for profit.