I wonder if it might depend on which POE you enter. I had also informed them of the intent of submitting the PR application and my spouse was with me. Might make a difference, who knows. Was just going off of what happened with me, trying to help.
I concur...and you were helping by being a part of the discussion!
There really doesn't seem to be much continuity regarding U.S. citizens entering Canada. CBSA has even been known to stamp the U.S. passport of a PR upon entry into Canada!
I was somewhat shocked to learn that, up until the final phase of the Beyond the Border initiative between the U.S. and Canada, citizens from each country were never really tracked when exiting their non-citizen country.
https://www.cbsa-asfc.gc.ca/agency-agence/reports-rapports/pia-efvp/atip-aiprp/eei-ies-eng.html
An Act to Amend the Customs Act, which received Royal Assent on December 13, 2018, establishes new authorities for the CBSA to collect basic information on all persons leaving Canada. Canada will implement the expansion of the Entry/Exit Initiative to include the exchange of Biographic Entry Data
on all travellers who enter either country via a land port of entry, including Canadian citizens, Registered Indians of Canada and U.S. citizens. Canada will also fulfill its commitment to develop a system to collect Biographic Air Exit Data
Footnote 3 on all travellers departing Canada directly from air carriers, similar to U.S. processes and systems already in place. These initiatives will be implemented once legislative and regulatory amendments are in force.
The final phase of Entry/Exit was implemented on June 25, 2020. The CBSA began collecting exit information on all travellers from air carriers. This information is not shared systematically with the U.S.
Together, departures in air and land modes represent 97% of exits.