I have realized that with San Diego, in the baseline configuration, import logs are not created when you import something using the transform maps.
In order to enable the import logs again, you have to create this property and set it to true:
glide.importlog.log_to_table
The complete documentation of the Import Set Properties is here:
https://docs.servicenow.com/bundle/sandiego-platform-administration/page/administer/import-sets/reference/r_ImportSetsProperties.html