Thank you. So just to confirm you didn't submit your sponsor's birth certificate and your application wasnt returnedThe sponsor's birth certificate is not required, the sponsor is not required to provide a PCC or fill out the Schedule A or fill out the Family form or anything. The sponsor is already a permanent resident or Canadian Citizen. The only time you need to provide their birth certificate is if you're using it as an identity document for the sponsor i.e from the section where you choose one from passport, birth certificate, citizenship card etc.
When they say provide for all family members (if applicable), the if applicable means if your spouse, children or their children are also part of the application process for PR. That line is normally for other forms of PR apps like Express Entry, Federal Skilled worker etc where you spouse is coming with you from your country. In the case of spouse sponsorship, your spouse it the one sponsoring you so you don't need that stuff.