Data transfer from old to new iPhone lost data of some apps

yqqqq wrote:

Should data transfer function transfer all data from my old iPhone to the new one?

Yes.

Though it is not clear how you are doing the transfer, I have this to say...

If you have already set up the new iPhone then the data created during this period will be lost if you use any of the three processes given below

iPhone to iPhone, there are three ways,

1. Quick Transfer --> Use QuickStart to transfer data to a new iPhone, iPad or iPod ...
2. Restore from iCloud Backup --> Restore or set up your device from an iCloud backup - Apple ...
3. Restore from iTunes backup --> Restore your iPhone, iPad, or iPod touch in iTunes on PC ...

Depending on the internet speed all apps will get downloaded from the App Store automatically. Apps don't transfer from iPhone to iPhone, only the app data along with app links to the App Store gets transferred.

Apps & Settings --> Apart from the Apps following will also not get transferred.

1. Content from the iTunes and App Stores or PDFs downloaded directly to Apple Books
2. Content synced from iTunes, like imported MP3s or CDs, videos, books, and photos
3. Data already stored in iCloud, like iCloud Photos, iMessages, and text (SMS) and multimedia (MMS) messages
4. Face ID or Touch ID settings
5. Apple Pay information and settings
6. Apple Mail data
7. Apple Music