Most of the embedded function calls have valid results in their previews, so my guess is that it’s the global cache (in error) that blocks the display of the (successful) preview result.

The simplest workaround appears to be changing the language from Z1430 to “de” in each function call, but if this approach is adopted for too many functions at one time, you will probably encounter a rate-limiting problem.

If the original problem was caused by a rate-limit applying to multiple function calls, those errors should not be cached (or not for long).

I think there are a few issues here:

• Calls are cached for a long time, but without a CTA/purge ability to fix.
• The errors are entirely unclear and give you nowhere to go to understand what's wrong.
• The errors being cached is not ideal
• The stampede of many renders at once likely causing the issue is particularly bad.

Change #1214499 had a related patch set uploaded (by Genoveva Galarza; author: Genoveva Galarza):

[mediawiki/extensions/WikiLambda@master] [WIP] Reduce failure TTL at both client and repo sides

https://gerrit.wikimedia.org/r/1214499

Change #1214499 merged by jenkins-bot:

[mediawiki/extensions/WikiLambda@master] Reduce failure TTL at both client and repo sides

https://gerrit.wikimedia.org/r/1214499