Not all apps will transfer:
Here's what gets transferred: contacts, message history, SMS messages, camera photos and videos, photo albums, files and folders, accessibility settings, display settings, web bookmarks, mail accounts, WhatsApp messages and media, Voice Memos, call history, and calendars. If they're available on both Google Play and the App Store, some of your free apps will also transfer. After the transfer completes, you can download any free apps that were matched from the App Store.
From https://support.apple.com/en-us/118670
Provided that you have your current. device, you can try transfer again