twn:/srv/mediawiki/workdir (master)$ php maintenance/shell.php 
>>> var_dump( $wgUseInstantCommons );
bool(true)

Nothing related to instant commons in error or debug logs.

cdf7207df823269bea217a50c765e36d5278786b is the first bad commit

commit cdf7207df823269bea217a50c765e36d5278786b
Author: Derk-Jan Hartman <hartman.wiki@gmail.com>
Date:   Wed Jan 26 01:01:36 2022 +0100

    Support audio on filepage in InstantCommons
    
    The transform for ForeignAPIFile generally delegates transforms to the
    thumburl of the remote. This works well, unless the file in question
    has no inherent visual area, like audio files. Audio files on the file
    description page when using InstantCommons have a 0x0 size, and the
    Commons API returns errors for thumbnails of 0 size.
    
    Instead, since we already know we don't need a thumbnail url for audio
    fragments, just skip that step directly and simply pass an empty
    string thumburl to the HTML generator of TMH.
    
    Bug: T300085
    Change-Id: Iea0e16de97e5e5da8c84bdbed8a2961ad194c040

 includes/filerepo/file/ForeignAPIFile.php | 19 +++++++++++++------
 1 file changed, 13 insertions(+), 6 deletions(-)

I have reverted rMWcdf7207df823: Support audio on filepage in InstantCommons on translatewiki.net, so the example link no longer works.

I will take a look

Change 758924 had a related patch set uploaded (by Ladsgroup; author: Ladsgroup):

[mediawiki/core@master] Revert \"Support audio on filepage in InstantCommons\"

https://gerrit.wikimedia.org/r/758924

Change 758925 had a related patch set uploaded (by Ladsgroup; author: Ladsgroup):

[mediawiki/core@wmf/1.38.0-wmf.20] Revert \"Support audio on filepage in InstantCommons\"

https://gerrit.wikimedia.org/r/758925

Change 758925 merged by jenkins-bot:

[mediawiki/core@wmf/1.38.0-wmf.20] Revert \"Support audio on filepage in InstantCommons\"

https://gerrit.wikimedia.org/r/758925

Mentioned in SAL (#wikimedia-operations) [2022-02-02T18:16:16Z] <ladsgroup@deploy1002> Synchronized php-1.38.0-wmf.20/includes/filerepo/file/ForeignAPIFile.php: Backport: [[gerrit:758925|Revert "Support audio on filepage in InstantCommons" (T300751)]] (duration: 00m 51s)

In T300751#7671900, @Nikerabbit wrote:

I'm lowering priority since this is mitigated at translatewiki.net. Feel free to adjust the priority further as is appropriate.

It was made a train blocker so should have remained UBN! It's no longer blocking the train though thanks to @Ladsgroup's revert

I have moved it to blocking next week

ugh. && should have been an || of course. Will fix

Change 759765 had a related patch set uploaded (by TheDJ; author: TheDJ):

[mediawiki/core@master] Correct condition for InstantCommons with 0 dimensions

https://gerrit.wikimedia.org/r/759765

Change 759765 merged by jenkins-bot:

[mediawiki/core@master] Correct condition for InstantCommons with 0 dimensions

https://gerrit.wikimedia.org/r/759765

Change 758924 abandoned by Ladsgroup:

[mediawiki/core@master] Revert \"Support audio on filepage in InstantCommons\"

Reason:

not needed

https://gerrit.wikimedia.org/r/758924

Thanks for the quick fix!