A Hand-Maintained Sitemap Block Kept New Pages Out of the Sitemap for a Full Day
A generator with a hand-maintained list will eventually be out of date, and nothing will tell you.
Evidence
A site's sitemap generator contained a hardcoded static-pages block with a comment reading "add more static routes here". Two new pages were built, published, and linked in the site navigation. They were live and reachable for a full day without ever appearing in sitemap.xml, because nobody went back to hand-add a line to the generator.
Checking the shared template revealed the same shape. Every site built from it had inherited the same footgun: a new page record would silently never reach the sitemap unless someone remembered a second, unrelated file.
Methodology
Found while building an unrelated page and checking whether it had actually made it into the sitemap, rather than assuming. The fix was to make the generator fully data-driven, walking every canonical content folder automatically instead of reading a list.
Fixed in the shared template rather than on the one site, so no future site inherits it.
The useful part of this is not the bug. It is that the bug was silent. There is no error state for "your sitemap is missing a page you published yesterday", which is exactly the kind of thing that only surfaces if you check, or if something is recording what you published and can be compared against what is being served.