Hi mitch63,
It sounds like your old setup had things nicely automated, so I get why it's a bit of a head-scratcher that the new drive isn't playing along. I'm hoping one of our legends here in the Community might jump in with a workaround or something similar they've seen before. That said, since this involves your external drive and how it's interacting with your Mac, your best bet would be to have your IT crew take a look. They'll be able to check things like drive formatting, permissions, and whether the backup path is still set up properly in AccountRight.
Regards,
Sai