Connection to Old Iphone Keeps Disconnecting

Dear Community

I am trying to set up my new iphone using the quick set-up (start-up) feature. I am able to connect the two iphones but half-way through the data transfer, I get a message that the connection to the old iphone has been lost and I have to reset.

I have tried it several times without success. would really appreciate your support and advice.

Best regards

Saban