I have created an index in Libre Office Writer by manually selecting an entry and adding it to the Entries box. The initial result was fine. Upon saving, closing, reopening the file and updating the index I have noted that all the entries have migrated to the 1st key box and have gained a colon. The index now places the page numbers on a separate line from the entry. It has also created a problem for book formatters upon exporting to pdf. I do not understand this problem. I would like to fix it without hand changing each entry. I would also like for this to not happen again. I am on Windows 10, Version: 18.104.22.168 (x64), saving in docx format.
(Edit: activated screenshot -AK)