Hi chadgraham@cogmedix.com,
Hope you are doing well. Which MIFARE are you able to communicate with? You can see the Communication Principle of the NTAG212 in section 8.4 of the Data Sheet.
The CLRC663 plus is able to communicate with the NTAG212, as the reader supports the ISO/IEC 14443A , and the tag is designed to fully comply ISO/IEC14443 Type A specifications.
Best Regards,
Ricardo