After a few days of writing/re-writing drive images, it appears the solution to the original problem is don’t change the user name if you’re using the Raspberry Pi Imager.
The user name is pi and must not be changed.
That’s why Etcher works. i.e. there’s no way to change the user name when writing the
image with Etcher.
It’s OK to change the other RasPi Imager options:
- Enable SSH
- SSH password
- User password
- Configure wireless LAN
- Locale settings