Thank you so much. I did received the med request. 1 hour after I received the first email for PCOn this question
1. do I need to submit 5406 again? There is nothing to update...
The only thing I can think of check your form either it's the latest one or the old one because CIC/IRCC has updated this form(5406) in May 2018
2- Sometimes you get the medical request after few days - it depends.
Hope this helps