How to stop a short dashed line from becoming solid?

I just updated to Win 10, and when I add dashed lines to my LO text document: ---------, when I hit enter, return etc. it turns solid and crosses the page and is really difficult to remove only to have it happen again. Can not find setting to change this

Thanks

Tools → AutoCorrect → AutoCorrect Options → Options tab → uncheck “Apply border.”

BLESS you!

After having hit the ENTER key (and getting the unwanted border):

You also could hit CTRL+Z (step back) and the border is substituted by the original hyphen-collection.