Thanks for the report, Vimmington!
I could find the game and it got stuck on me as well. I guess the 2 effects (Gain Curse due to opponent's Swamp Hag, trash Treasure from buying Mint) never made it to the UI, for whatever reasons. I'll try a few more combinations, to see if there is a more general problem.
ADDED: It seems that Mint is the problem. In other combinations (with Haggler or Talisman) it works, but doesn't show UI (only for Haggler/Talisman).
The answer to why the game sometimes asks you to pointlessly make a decision between 2 effects that doesn't matter is that the game is not smart enough to know that it doesn't matter. And each new expansion creates new ways for things to happen where it can matter, Innovation for example brought to light some bugs that simply couldn't be observed before because no effect existed that allowed a card to be played that soon after it was gained.
For future bug reports, it would be very welcome if you could include the game ID. It's printed at the top of the game log and the start of the game's chat. The latter you can also access during the end-of-game screen (maybe you need to scroll up a bit if you chatted).
The DomBot on Discord can find your latest games (that's what I used), but is restricted to games against human opponent's and AFAIK will not find your unrated games after a few days. It just immensely helps to look at the original game with the problem, because the cause may be something that is not apparent to the players (like a beginning player may have forgotten to mention the Swamp Hag).
As I said in the beginning, thanks again for the bug report!