Thanks
@Alpsh !!
Finally linked my application. The tricky question is the last one: how many family members on the application. In my case: my mother-in-law as principal applicant, my wife as a sponsor, me as co-signer, 3 kids as dependants, my mother (applied for both at the same time). The correct answer is not as in question 7 in form IMM5768, but actually 3 to link the application finally!
Username : ikarib
Sponsored : mother-in-law
Parents Country Of Citizenship : Kazakhstan
Province : Ontario
Invitation Received: April 24, 11AM
Application sent to IRCC: April 26
Application received: April 29
E-case status for sponsor: AOR on May 30