Editing a document from Word (docx) on Writer then saving and opening it again on Word makes the document always on read-only mode, then I have to create a copy and edit the copy. Is there any way to fix it? The format I save on Writer doesn’t matter, either being docx or odt I have to create a copy of the file to edit on Word. My OS is Windows 10 btw.
Writer might not be closing it properly, probably Writer is crashing instead of closing.
What version of LibreOffice (Help > About LibreOffice)?
Test in LibreOffice Safe mode (Help > Restart in safe mode), make a small edit, save and close. If file opens OK then it might be a User Profile problem.
Make sure that the document is not still open in LO Writer, even if you have saved it, before trying to open it in MS Word.