A CSV file was created as below and then imported it into the Device Certification dialog. Even though the Model Type was defined as Switch in the CSV file, the Device Certification shows as Auto after the file import.
"CA Override","Vendor Name","System Object ID","Device Type Name","Model Type","Model Class","Modification","Author","Support Level"
"Yes","Cisco Systems","1.3.6.1.4.1.9.1.1390","Cisco 886Vag7K9","Rtr_Cisco","Switch","","Unregistered","Enhanced"
"Yes","Cisco Systems","1.3.6.1.4.1.9.1.1754","Cisco catalyst296024LT","SwCatOS","Switch","","Unregistered","Enhanced"
Release : 10.4.1
Component : Spectrum Certification
Engineering has identified the problem and fix for the same will be available in the next release (The next release likely to happen in the next 3 to 6 weeks). After the fix, ModelClass attributes will be populated correctly.