It is likely that the termination occurred because of a service timeout. After step 20, the installer tries to set up services on the cluster. These services are pulled from a docker container to be installed. It is likely that these services failed because of a predefined timeout.
There are many steps in the installation process which will take nearly hours to install, the reason is that installer tries to reconnect to these services but connection just times out. At this moment, the timeout periods are not configurable, we have raised this issue with the engineers from IBM.