Hi paulg47,
The time it can take to move to iOS , depends on how much data need to be transferred over. If it is taking longer then expected you can try restarting your devices in order to force the process to restart.
1. Press and hold either volume button and the side button until the power off slider appears.
2. Drag the slider and wait about 30 seconds.
3. Press and hold the side button until the Apple logo appears to power it back on. Once back on, test to see if this continues.
Check out: Restart your iPhone- Apple Support
Hope that helps!