It's a well known issue, that you can't change the canvas size, when smart filters (like liquify on a smart object e.g.) were done.
There should at least pop up a warning, if any smart filter is detected and the user is going to change the canvas size or doing any other action, that will result in wrong recalculation of the smart filters.
These small filters were mostly hidden, even when you look at the layer you have first to open the small panel. So this is always a dangerous trap.
I can't count how often I had to rework for hours, because there have been nested objects with smart filters, that have been forgotten by someone.