No video with supported format and MIME type found. NS_ERROR_DOM_MEDIA_METADATA_ERR (0x806e0006)

I'm not the only user experiencing an issue playing back various videos that were previously supported and working.

In current Firefox builds, at least on my system, when loading a video I see the following:

No video with supported format and MIME type found.

In the Console window this is the only text of note. NS_ERROR_DOM_MEDIA_METADATA_ERR (0x806e0006)

Here is a test case video https://dl6.webmfiles.org/big-buck-bunny_trailer.webm

There appear to be two Firefox bugs already https://bugzilla.mozilla.org/show_bug.cgi?id=1887735 https://bugzilla.mozilla.org/show_bug.cgi?id=1892233

This Debian bug is likely related to the same issue https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1068126

I'd like to supply upstream with additional information if possible, the Debian bug doesn't mention where they found the data collection steps they performed. Further, IIRC from reading the report, in the non-working case they didn't capture any useful data from those steps anyway.