The problem was identified with this template:
https://github.com/apigee/microsoft/tree/master/apigee-edge-arm-template
Install finishes but sysadmin is not able to login into the Edge UI.
The rootcause is special characters ($!) 'are lost'/distorted in a password while the password literal is passed through CLI parameter/bash/sed.
It's a minor thing, but stings badly anyone who is caught in it, which means practically anyone enterprise who have password policy to avoid simple passwords.