Michael, you are correct. The recommended expression is for the recommended standard GEDCOM Census (CENS) event.
That is why it works for Adrian.
Your facts are non-standard custom facts, so those recommendations won't work and you need different expressions.
Would you consider converting all your custom Census facts to use the standard GEDCOM Census event?
The benefits are explained in FHUG Knowledge Base
Recording from a Census Record article.
All the FH Census tools and examples in the FHUG Knowledge Base assume the use of the standard Census event.
There is a Plugin that makes the conversion fairly easy.