Clicking on a card in hand while Poppet Stitcher's trigger is resolving results in an incapacity to do anything
This happened in a Premier Draft game.
Starting my turn, I had Poppet Stitcher in play, Electric Revelation in my graveyard and a Mountain in hand (+ enough lands to flashback Electric Revelation).
Upkeep happened, Poppet Stitcher's trigger was put onto the stack, but I was given no possibility to respond to it (I planned on casting Electric Revelation there) and it resolved immediatly. I did not have full control on, but I thought I could respond to my own triggers despite that.
When being prompted to choose whether to transform Poppet Stitcher or not, I clicked on "View Battlefield", then on the Electric Relevation in my hand because I wanted to try to cast it (which is not possible during the resolution of Poppet Stitcher's ability, but I was confused due to what had happened before). After that, I couldn't unclick the Electric Revelation, and clicking on "View Browser" didn't let me go back to the decision screen for Poppet Stitcher's ability, resulting in me being stuck in the game.
I had to restart client to get rid of this bug, making me lose an extra time bonus.