If you have already created the terms in your Subjects taxonomy, and when importing a descriptions CSV, your subjectAccessPoints terms in the CSV are not properly linking to the matching terms in the taxonomy, then:
The most common reason for this is a mismatch in the culture values. For example, the terms were created in the English user interface, but the CSV uses es as the culture value for all rows. When this happens, a match won't be found, and
Make sure your subject terms were created in the same culture as the CSV rows - or else, add translations in the appropriate culture. Make sure as well that the culture of the user interface (which can be set using the Language menu
) matches both the terms and the CSV rows when you run the import. In some cases, user accidentally create subject terms in a different culture (for example, using the English user interface when creating a terms, even though the installation culture is Spanish), which can lead to these issues.
Let us know if this helps you resolve the issue!