Printer metrics for document formatting

Greetings.

I want to disable the setting “Use printer metrics for document
formatting” in Libre Office Writer (Libre Office 6.0.3.2 on Ubuntu
18.04). When I deselect it it is automatically selected again every
time I open a document, whether a new document or an existing one.

I have made the change in each of the relevant documents and also in
the default “New.ott” (~/.config/libreoffice/4/user/template/New.ott),
but to no avail.

Is there any way of fixing this?

Many thanks.