Consistently saving the cursor position in Writer (6.4)

I followed the instructions to save the position of the cursor in an ODT file. I have followed the many postings on this topic over the years so to avoid duplication and obvious things e.g. it only works with ODT files and not DOC etc. I will try to be as precise as possible. The steps followed are as follows

  1. My first/last name were filled in: LIBREOFFICE - PREFERENCES - USER DATA
  2. I created a new file: FILE-NEW-TEXT DOCUMENT.
  3. I pasted the contents of an old ODT file into the new file, some editing and formatting took place.
  4. I saved the new file
  5. I checked the new file and indeed under FILE-PROPERTIES-GENERAL my name is noted under the created and
    modified lines
  6. Exit the WRITER
  7. Double click the new ODT file to open WRITER and Wow! the cursor is at the saved position!

I did it again with different content into another new file - initially it worked, but after some editing and format changes of the content (e.g. changing the font size) the save system unfortunately stopped working and the cursor on reopening is at the top of the file, not very practical in a document on 80 pages. One document works and one unfortunately has stopped working.
I have no idea why, any advice would be most welcome.

Some background
I only use “new” ODT files. I have never got the save system to work for ODT files that were created by importing a doc file and then saving them as ODT. This is repeatable, there seems to be some fundamental difference between ODT made as new as in blank/empty and then filled with content and ODT made by opening a DOC file and saving it as ODT.
I use LO 6.3 on Windows 10 and LO6.4 on an OS, the behaviour described above is the same on both machines with both files.

That would need a bug report with a sample document where the cursor doesn’t get restored.

Thanks for the quick response and feedback I have prepared a test file and submitted it with a bug report as you suggested.

@HughD - it is a best practice to leave a reference to a bug report, if created based on a question on this site (here: #tdf130418)