@Patsyblefebre and I cobbled together a replacement for the automatic page generated for new users. (The original was rather anemic and the linked “help pages” were on the MediaWiki site. Not really helpful for our wiki.) That original welcome page only contained what is in the yellow box below.
That is the one we thought it was. And Sam put the template in it during Nov 2021. When that didn’t work, we suspected there was a technical problem that did not recognize Transclusion templates in the automated response system. So we tried pasting in the message.
Still no joy.
Looking at the talk pages in the user creation log, all of the places where the Onboarding Survey is in the new user Talk page is from one of us manually inserting it.
I wonder if… with all the backups, mirrors, and upgrade attempts… maybe the configuration for the system actually doing the automated response and the one tracking the Special Pages are pointed at different directories?