Thanks for the scan. CBSA is hopeless. (I wish there was a facepalm emoji in FT.) They provide hard documentation to update passport with NEXUS office but prefix with check the GOES/NEXUS website which still gives contradicting directions. How difficult is it to get their act together and communicate a consistent message?
Please note that NEXUS members are not required to report to an Enrolment Centre to update or change their passport information with the CBSA.
. And website doesn't mention anything about faxing.