when printing to the actual label sheet the addresses are okay on the first line only and then progresses down the sheet printing outwith the label.
Your description leaves something to be desired. Do you mean that the printer prints a little bit outside the label? If yes, then it may be simply a formatting problem. You can format the font size and margins to keep the print inside the label.
From Libreoffice help:
Choose File - New - Labels to open the Labels dialog.
On the Labels tab page, select the format of the label sheets you want to print on. You can set the fontsize and margins in the text boxes provided for that purpose.