I cannot do a normal section page either All section- and page-break options are grayed out.

If I select the ",7,8," in 6,7,8,9 and press ctrl+shift+h the result is 69. If I place my cursor between 7 and 9 and press the "-" key, I get an "_" instead. However, I can copy a "-" from somewhere else in the text and paste it between the 7 and the 9. If I then select 7-9 and press ctrl+spacespar it changes back to 7_9 and not to 6,7,8,9.