Hi,
It is not due to the version, but a client can connect to only one Console. Client identifies the console using a private/public key pair.
Usually the scenario is you upgrade the 8.0 Console to new version. Then Console will retain the same certificate and upgrade the clients when you run a task.
In your case, you have installed a fresh Console of 2.01, and it generates a new key pair so the clients of 8.0 Console would not connect to it.
There are couple of ways to solve this, one easy thing is to copy the pubkey.crt and privkey.crt files from old Console to new Console after shutting down the old Console. YOU SHUOLD NOT HAVE BOTH CONSOLES RUNNING WITH THE SAME KEY PAIR since the clients will connect to the Console it finds first at each boot, and the results are undefined.
Second solution is installing the client using Remote Client Install from new Console on the clients of old Console. Then it will upgrade and copy the new credentials to the clent and they will connect to the new Console. However, this could be time consuming.
I think the best thing for you to do is to replace the pubkey.crt file in the Ghost folder of the old Client with the file from new Console. After restarting the machine (or the service), it will connect to the new Console. Console will indicate the version of Client is not the same as Console by putting an ! mark in the client icon. When you run any task (like refresh) it will update the client to the new version. You can do copying the pubkey.crt file and re-starting the machine by running a task from old Console.
Krish