MassimoP
When you upgrade to a minor release of the same major version (eg. v1.17.2 -> v1.17.5) the upgrader will not run. Reason being is there are no database patches added. When we add database patches we always increase the major version. On minor releases they are simply security and maintenance releases.
With this being said, if you upgrade to a new major version (eg. v1.17.2 -> v1.18.1) then the upgrader will be triggered.
Cheers.