OK, then I think we have to go into the systems preferences and make sure the new drive is selected as the startup drive within Startup Disk.
You may want to use this app instead [https://www.tunabellysoftware.com/tgpro/|TG Pro] as it will show you more details on whats happening with the thermal sensors and fans. If you get the full version the other SMC sensors are also monitored. I personally like this program better than the others.