Started Docker container for XWiki using mysql based docker-compose.yml (standard install, following web instructions).
Selected “Standard flavor” which installed okay.
I look at activity stream of my user and I have “Unknown Macro : notifications”.
I have not diverted from a standard install, so I presume this is easily reproducible?
I revisited it this morning - I found I had a typo in my docker-compose.yml that got introduced by my finger trouble, that made the path to the mysql xwiki.cnf file invalid - so the setup as you say was not working.
I removed the error and restarted from scratch with the file fixed, and it is all working - thanks for the push!