Solving a ticket concerning sitemaps app I've come across with an issue when I tried to generate a sitemap from web browser with Magnolia 5.5.2: There was a 404 page not found error. However, exporting the sitemap there was no problem.
Doing the same with Magnolia 5.5 there was no problem so I started researching and found that there was an improvement (Jira
MGNLGS-120) in gooogle-sitemaps module 2.4.2 (which is used by Magnolia 5.5.2) which had changed the value of the configuration parameter URIPrefix from /sitemaps to /sitemaps/. I tried again changing in the configuration app the value from /sitemaps/ to /sitemaps and after that, I could generate the sitemap from my web browser without problems.