OK...
So I got my first email from IRCC on my sponsorship application today. (For Dependent Child).
So, with all the info I had read from this forum, tried the link my application. (I am the sponsor and I was linking to my (sponsor) account).
Went in with the details as I submitted and I got the no application message.
Later after couple of hours, tried again (used the File # and Last name option). This time, the change I made in my search is, as many suggested here, put the number of applicants in applications as 2 (instead of 1).
Thank God, it worked. And dont be fooled... the search result page just says we searched with the informations and : an application was found.... in a normal font. It wont show the Application details. For a moment as I saw a blank area between two red lines (where I was hoping to see the application details), i thought it didnt work. But then when I read the info provided below, I was happy and then clicked the link my application. Thats it.
Now my kid's sponsorship application is showing up in my account.
Thanks you all for your info sharing.