Unsplash Wallpaper Issue

This is really a cool app & worked as expected for about a day, but now it's in a state where the menubar item no longer opens a window (screenshot) and clicking any ‘Set as Wallpaper' has no effect. Changing the wallpaper from System Settings changes what's behind the running UW (I can see the menubar change color). Tried quitting & re-opening, rebooting, trashing the app and reinstall from the App Store. Can’t find any preference file in ~/Library. MacOS 13.5.2, M2 MacBook Air.