I recently purchased an MG3620 and I can't seem to setup the printer using the wireless connection. The printer is not being found on the network. When I press and hold the wireless button (per on screen instructions) the on button does not flash once as it says it should on the screen. What really helped is a post at a website explaining the proper stpes for canon mg3620 setup. I ended up calling their team and they helped me in installing my canon mg3620 printer.
You can also check this post to connect your canon mg3620 to wifi without facing any issue.