Yes, I get the same, for all three apps when double clicking on an Affinity document.
I thought it was because I still had the version 1 set installed, when I installed the v2 set, but uninstalling all of those didn't help. In fact it made things worse, because prior to uninstalling them I would sometimes get the "How do you want to open this..." dialog. I know I can hack around in the registry to fix what we once called 'file associations', but that get harder and harder with each version of Windows and I'd rather not. FWIW, the large icon view of my document still shows the previews perfectly well, so something's working.
Simon