My recent software update has wiped my contacts. I have tried to restore contacts in iCloud but no archives? Old phone still has full list.

The software update that happens automatically when connected to power has wiped the majority of my contacts. I have logged into iCloud to Restore Contacts but no archives? The full list of contacts is still there on my old iPhone - how can I get them transferred over? And then get them backed up to the iCloud?

I have already tried switching it off and back on again but that hasn't worked.