Oh, that's weird then. Hm. Luckily, I had saved a old build where I had kept that broken code. So, in the field property that I used as a "source" for my dialogue I had !go["Next" "SlideLeft"] . And when I playtest it, clicking the widget that suppose to start the dialogue, whenever it got to that function, it will actually do the function but the program just cuts off before it reaches its full completion.
And abt the saving, it missed like little things here and there like if I had changed a word on widget or moved it elsewhere on the screen. (What's funny is that I just checked my current build, and I see that it didn't save one word I change in the final build I had up, haha. Pretty sure, I had the autosave on.)
Let me know if I should send you the old build itself or anything to help fix this! And thank you so much for the kind words, I'm glad you enjoyed the final product <33