The last photo of your three is what I type in. The past few times I've entered the URL in your 3rd image before logging in, brings me to login page, login, brings me to dashboard, click on my order, brings me to my order page, then I enter that URL in your 3rd image, hit enter and it loads the edit-design page which looks just like the order page on Tesla.com if you were to go place a new order but it shows older pricing (does have a $600 higher delivery fee since my March order) and it starts off with my exact ordered config unlike the Tesla.com new order page which always starts off with white exterior and 20" wheels and not MSM color and my 19" wheels.
I'm confused why it isn't working for you. It may be that Canada does have a more recent cutoff than the US because Canada only got the option to keep old pricing a month or so ago and the US has had it since October or November? I think.
I'll add that once it actually loads the Edit page the URL shown in the top bar is this:
https://www .tesla.com/en_CA/modely/design/RN11#######?redirect=no&redirect=no#overview
You could try typing that directly with your RN#. Remove the space after www as I added that so the forum didn't create a hyperlink.
Screenshot of the page with the March 11th pricing plus the $600 extra for delivery.
View attachment 822645