Why on earth would someone install Rock and immediately try upgrading to ROME? If you believe you want ROME install that.
As I tried to say upgrading from Rock to ROME is unfortunately not straight forward and simple. I suspect this is the problem you saw but can not say for sure with out evidence like terminal output or logs.
If we had evidence of the actual problem there is possibly a fairly easy fix. But we need evidence.
Edit: I am chasing this problem because I thought that problem with systemd was fixed but if it isn’t we need to get devs involved and see if it can be fixed. If you just want to stay on Rock, the safe choice admittedly, that is OK, I can understand that.