I have noticed that a show column will not display when
UX> Options> Detail View - is ticked to “Include Show columns in detail views. Include Show type columns in detail views, not just form views”.
In UX> Views> System Views - when looking at a Detail view e.g. [my view], if you try to rearrange under Column Order and finish with the option of all other columns, every Show section header after that point will not be shown, but interestingly, anything before all other columns will show the Show section header.
The only fix is to add every column and end without putting in all other column option.
Therefore under UX> Views> System Views > [my view]> Display mode> …the No headings option is redundant as it will not show the heading anyway!
A little bit of a pain, but I wonder if I am doing something wrong or if this is a bug?