This fix was in the release notes:
Portuguese SEP clients do not update with AutoUpgrade when their Portuguese SEPM migrates from 12.1.x to 14
FIX ID: 4016906
Symptom: After migrating a Portuguese Symantec Endpoint Protection Manager from 12.1.x to 14, the Portuguese SEP clients do not upgrade from SEP 12.1 using AutoUpgrade. The version 14 setAid.ini file is configured with ClientLanguage=Brazilian; however, the SEP 12.1 clients are configured with ClientLanguage=Portuguese, which results in a language mismatch.
Solution: Now allows an AutoUpgrade if there is a language mismatch between Portuguese and Brazilian. Changed the ClientLanguage setting on the client from “Brazilian” to “Portuguese” for the client to avoid future mismatches.
Not sure if it applies to you and if not you'll need to get a case open.