After the latest (November 2025) update, when I try to split a polygon with the "Allow splitting without a selection" box checked, I get the following error message, "Splitting features failed.
A polygon cut operation could not classify all parts of the polygon as left or right of the cutting line."
If I select a polygon and try to split it with the "Allow splitting without a selection" box checked, I get the same error. I can only split the polygon without the box checked and polygon selected.