I just had to send something to another country and wanted it to be tracked and to get there fast. The guy form Canada Post said to send it for registered mail (which is not as fast as Xpress) because he said mail is moving slow anyway due to COVID and paying extra wont assure it gets delivered within the time frame it normally would. It is quite possible that your documents just haven’t arrived yet.
Just so you have an idea, the file I sent would normally take 3-7 business day, but the guy said it would take up to 3 weeks.
Good luck, and just keep on checking the status.