Game #3607252 on frankfurt. edit: Actually #3608195 on oregon (sorry)
On the previous turn, my opponent plays a Royal Carriage and a Hamlet.
With a Royal Carriage on my opponent's tavern mat, I got this prompt at the beginning of my turn:
Turn 10 - Dwedit
It's your action phase, you may...
• play an Action from your hand.
• Call Royal Carriage
If I chose to call the Royal Carriage, it played a Hamlet, my opponent drew a card, and I got the prompt of whether to discard things or not.
Then I did an undo. The prompt to call Royal Carriage returned, then I ignored it and played the rest of the game normally.
The prompt for me to call Royal Carriage did not appear again after that.