Query on http profile in Virtual Server.

If you add an http profile to a VIP on 443 then you must also add a client ssl profile.

This puts your bigip in a MITM mode means it can decrypt the encrypted packets.

Depending on your backend you might have to use a serverssl profile too if the backend is on 443 as well, which I am guessing it is because when you create a VIP on 443 without a http profile, its acting as a SSL bridge with your backend server which also needs to be on 443. Means your bigip cannot see the encrypted data.