In some cases, what will happen is a lead will enter through the Facebook Lead Form and submit their name, email, and phone number. This lead will then be submitted to your CRM with that respective name, email, and phone number.
After being redirected to their Qualifunnel, the lead will fill out the information and be asked to confirm their email, name, and phone number again. At this point, after completing about 10 questions, since they've invested so much time, if they're already entered a fake/wrong/different email that they previously entered, they are likely to correct it at this point
In some cases this looks like:
Inputting their email instead of the spouses, etc.
Inputting a correct phone/number as opposed to a fake one, etc.
When leads do this, it may cause some additional profiles to appear in your CRM and should be seen as a normal part of building trust with consumers online.