I'm 35K status and as far as I can tell, a core benefit of 35K for 2026 is Preferred Seat Selection at *check in*.
I've noticed that if I don't select any seat prior to check in, the automatically assigned seat at check in will usually be a preferred seat (cool) and I won't be charged. However, I can't actually change the seat - any attempts at changing the preferred seat to another preferred seat (eg window to aisle) results in Air Canada attempting to charge me the usual preferred seat fee of 80$ or whatever for the flight.
This seems broken - shouldn't I be able to select any Preferred seat upon Check in? Has anyone else noticed this?