I accidentally marked the don't ask again tickbox in the window that pops up when you click on stop polar alignment and then accidentally pressed no. Now I cannot stop the polar alignment because it assumes I don't actually want to do that.
How can I make it open that pop up again, or alternatively how I can change the 'answer' I gave?
My guess is that (at least on Linux) you would look in ~/.config and hand-edit one of the files in there.
For instance, I see ~/.config/kstars.kmessagebox which looks like it likely is the thing that controls these 'don't ask again' things.
Perhaps remove a suspicious line from that file and restart kstars.