Congratulations for hitting many milestones in one week. If you don't mind me asking I thought the Nexus enrollment centres in Canada are still closed, how were you able to get an appointment? Also, how did you manage to register for Nexus prior to obtaining a Canadian Passport, do you currently have an American passport or entry visa?
Thank you for your response and apologies for not posting in the relevant thread.
The Nexus enrolment centres in Canada are still closed - when I looked for an appointment through the booking system I had the option of virtual or in-person. I selected in-person and the only available locations that showed up were Detroit (4 hr drive from Toronto) and 2 locations in Minnesota (18 hour drive).
There were quite a few days available for Detroit, so I booked one that was available in August. It appeared like they had just released a batch of new appointments because only morning timeslots were available on Thursdays and Fridays. An hour after I booked my appointment all slots appear to have been claimed and nothing was available at the time (except for the Minnesota locations, still).
I applied for Nexus last year as a PR hoping it would be approved sooner and before I became Canadian. I had to wait until last year because of the physical presence requirements for Nexus and Canadian PRs. I already had Global Entry with my Netherlands passport so I thought being in the system would speed things up. It didn't, so my Canadian Citizenship came before the Nexus approval. Once you apply for Nexus you cannot update the system with new information, so it still shows my PR Card and my Netherlands passport as part of the application.
I'll have to explain to the officer in my interview why I don't have a Canadian PR Card any more, and I hope they can update my info in the system with my new Citizenship. I've emailed CBP to find out what I need to do. I'm hoping to get an answer soon.
With my Netherlands passport I can enter the US under the Visa Waiver Program - but now with the Canadian passport I'll enter as a Canadian to go to the appointment.