amp-facebook no longer working for videos

### Description

I'm not sure if this is more an AMP or a Facebook issue, but having redeveloped my website as AMP, I've found Facebook video post embeds are no longer working. The component renders correctly, but returns a 'Video unavailable' issue.

This was not happening a number of weeks ago when we implemented the embed, but is now we've come to launch the site into production.

We've tested various videos and various URL formats, all with the same results. The Facebook standard HTML embed equivalent is still working fine.

### Reproduction Steps

Three examples here:

https://www.comedy.co.uk/online/videos/21854/covid-vaccine-side-effects/

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https://www.comedy.co.uk/videos/21184/sian-harries-ac-esyllt-sears/

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https://www.comedy.co.uk/online/videos/23279/the-vegan-tudor/

```

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### Relevant Logs

_No response_

### Browser(s) Affected

_No response_

### OS(s) Affected

_No response_

### Device(s) Affected

_No response_

### AMP Version Affected

_No response_

Start with the amp-facebook component and reproduce the three supplied Facebook video embeds, comparing their behavior with the working standard HTML embed. Determine whether the component or the Facebook video endpoint changed; done means the reported video examples render successfully without the “Video unavailable” result.

Written by the indexing model from the issue text.