Error message

Hello

1-I backup my desktop system to My Book 1T with Acronis.

2-I safely disconnect the drive and then back up my laptop with it.

3-When plug the drive back into my desktop, I get a message from Acronis which says, "You are not fully protected and need to back up.

Acronis seems to sense that a new drive has been detected and needs to protect it.

I contacted Acronis uet have not resolved this.

I actually have to do another backup to remove the error message

Is there any way you can think of to avoid this?

Thank you