It seems that Manual Cell Grouping is broken in 18.104.22.168 (at least in Linux). If one pastes a cell, then any cell bracketing gets "chopped" at the paste position. This bug affects a large project of mine, so I'm looking for a work-around using Automatic Cell Grouping.
I could probably find such work-around if I knew how to use the cell option CellGroupingRules. This option is not yet fully integrated into Wolfram Language, and as such it has minimal documentation. Can anyone provide some insight as to how to use this option? Or perhaps give a usage example?
Solving the following problem might suffice: Suppose I have defined a cell style called MySection (my own special section header cell). How can I get Automatic Grouping to treat a MySection cell in exactly the same way as a Section cell in terms of grouping precedence (assuming that cells with style MySection and Section are both being used in the same notebook).
BTW, I have sent a bug report to Wolfram support about broken manual grouping (the bug was introduced in 22.214.171.124, no such bug in 11.3).