How to activate the changes in the dicomcfg.xml in our sites

We added some AbstractSyntax SOP class values in our dicomcfg.xml file and restarted the process and later we also restarted the site.

When we try to choose the new SOP classes in the configuration properties of de dicom thread we still see a list of the standard classes but the new ones are not available.

Question: what do we have to do to make the new values visible in the list of SOP classes