Changes in sections and page breaks upon saving

I’m editing a 306 page ms. with lots of double-column sections. LO, Win 10. When I save and reopen, some of the page breaks are missing, putting the chapter heading at the bottom of the previous page. Also, many of the double columns, which had the text lined up before the save, have the two columns unaligned. This is a persistent problem, and I’ve not found a solution. Could it be a bug?
Attachments:Before.jpg before and after screenshots
The “Friend of Failure” is formatted as Heading 1, and does not include a page break. I mange them with Ctrl-shift.
Picture is anchored to paragraph. I’ve never read that it is a bad idea to use Default Style for text. And do you mean Text Body? Here is an after screen print with format marks showing.After with format marks.jpg Thanks for your comment.
I save in odt format.

You don’t use View>Formatting Marks, so it’s difficult to tell where the “forced” page breaks are if any. Is your “Friend of Failure” styled Heading 1? If so, does it force a page break (see Text Flow tab in the definition). It is also a bad habit to use Default Style for document content instead of Text Body. How’s your picture anchored (page, paragraph, character)?

Please answer through editing your question.

You save in docx format, right? Don’t.

As can be seen from your latest screenshots, your paragraph placement in the page/columns is done with empty paragraphs. This is not the correct way to do it because you become vulnerable to any “environmental” change such as margin, font size modification or even tiny picture change size/position due to rounding during internal computations.

To jump to next column, Insert>Manual break, Column break option. Though this is direct formatting, it may be tolerated if it is not too frequent. When you have a systematic use for it, create a new paragraph style with the break option in Text Flow tab.

Similarly, since your Heading 1 should always be positioned at top of a new page, modify built-in paragraph style Heading 1 to add the page break in its Text Flow tab (since your karma is presently 140, I assume you already know how to use and customise styles).

By using the Text Flow features, you can remove all your spacing empty paragraphs. The file is cleaner and its structure becomes apparent.

Default Style is the ancestor of all other styles. It is intended to define formatting defaults in supplement to “system” defaults set in Tools>Options. Its attributes are considered general enough so as to apply in all circumstances in all styles. From there, other style families are derived: Heading (again not to be used routinely, usually changes the font face for headings), Index for all generated tables (TOC, indexes, bibliography, …). You pick a style from a family for a specific usage (Heading 1, Heading 2, …).

Text Body is the “standard” style for typing text. It is also the ancestor of all document text styles so that they all have a consistent look. For example, List (not to be used routinely) defines global adjustments for all bulleted/numbered lists; then you pick a style for a list like List 1 or Numbering 1.

This inheritance feature is a very handy tool for formatting documents. It is also very powerful when you want to change the appearance without hunting for direct formatting occurrences throughout the text.

You can see the style dependencies in the styles side-pane when selecting Hierarchical view.

Many thanks. I discovered, through reflecting on your good questions, that I had treated the page breaks sloppily and had carelessly deleted many of them. Your explanation of the Text Body is very helpful. Many thanks again!

You’re welcome. Don’t forget to check answer and or vote. Thanks.