Created attachment 78727 [details] Shows borders before and after saving
When saving a document as .xlsx border thicknesses are altered. In the attached image you can see borders with a thickness of 0.05pt on the left (before saving), when opened after saving (see right image) they have been changed to 4pt. This seriously effects the layout of forms and spreadsheets generated in LibreOffice for later use in Excel!
*** This bug has been marked as a duplicate of bug 58356 ***