App Store not showing purchased Apps or side bar

When opening the App store on my mac i only see the screen you get when not signed in - even after I sign in.

Selecting Apple>Store shows me as signed in, and i have tried signing out and back in but I only ever see the page you get when not signed in.

It means I cannot see any purchased Apps, or re-install them.

I have tried in Recovery mode but that is no different. I can install new free Apps.

I have a Mid 2011 mac and am running the latest version of OS for my machine - High Sierra 10.13.6

any clues what is going on, and how to solve the issue?

TIA