iPhone upgrade lost some contacts (using icloud)

Migration went fine, except some newer contacts (from the last several years) on the old phone didn't come over to the new phone. I used the iCloud migration from a recent backup. I logged into iCloud & it only seemed to have the older set of contacts. So in summary: Old phone still has all contacts, New phone has some (older) contacts and iCloud also has some (older) contacts (same as New phone).

I want to get my contacts from Old phone to both the New phone and iCloud before I get rid of the Old phone. What's the best way to do that? Or is that even possible?