OK. I got things working but I am not sure what this issue was. I started calamares in debug mode again and decided to walk away for a while (like half hour). Eventually, the partition module must have loaded. I proceeded with the installation but it failed making a partition.
So, next I deleted all of the existing partitions on the target disk. I started calamares expecting to have to walk away again and there was no waiting for the partition module and I could proceed. The installation was fine.