@matdevdug when i wanted to transfer with quickstart my old iphone to my new iphone, i first wasted a lot of time.
i then called with Apple Support and complained why the app is called *quickstart* while the transfer takes forever?
Answer:
First set up the new iPhone as empty/new. Then perform the iOS update. After that, reset it to factory settings. The currently installed iOS version will remain intact during the reset.
Then update the old iPhone to the same iOS version as well. After that, use Quick Start.
Worked flawlessly: The eSIMs will automatically transfer to the new phone too*, and amongst other apps WhatsApp as well.
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*) it even converted one physical SIM in old phone to an eSIM in new phone


