In recent Mathematica notebooks, if I have a cell with several sub-cells, insertion of a new sub-cell in the middle breaks the outer containing bracket. I can recover by ungrouping and regrouping things, but where can I read about what the intended use of the bracket-breaks is?
I couldn't find a solution related to that possibility. Here is an image with different sub-cells and an outer bracket line that is "whole" on top. On the bottom, when a new cell with its own sub-cells is copied into the middle of that, the outer bracket becomes only partly visible. It is still there since subsequent removal of the new entries restores the outer bracket. The old behavior was that the new entries would just give further nesting without a break in the outer cell bracket.
By "breaking a cell", do you mean that the cell is divided into two lines? If so, you may try the LineBreakWithin -> False option, perhaps within a Style:
LineBreakWithin -> False
Style
Style[mycells, LineBreakWithin -> False]
