I just finished shopping and now there's no dungeon to sweep anymore. Even if I reload the page and choose "Load game", I will see the banners for each of my items but no dungeon.
I got the same issue and pasted the console into this pastebin: https://pastebin.com/m2XRCjru
Hopefully that helps with a fix.
It happened when I clicked continue to get out of the shop and to the next stage, the shop overlay did not disappear and I could keep clicking continue. In the background I saw new bigger dungeons being loaded until the nothing screen showed up. Also I was able to click the tiles in the dungeon in the background of the shop which was a bit weird.
Here's my inventory ah the time