Cut & Paste website text into a Writer-doc: gray-options shown.

When we open Writer (v. 5.1.4.2) at Ubuntu 16 04 LTS and adding into a writer doc some website information
then reformatting it by select all text , font Liberation Serif will mash up the font-size box. The fontsize box does not show any number any more in a gray pulldown. Just selecting gives "2 " (indeed some kind of spaces).
When you want to Save the document the whole save box is gray, you will not see any Save button (all-though it is available).

Work-a-round is selecting first whole text with style option “Clear formatting” and as second define the required font and size. This is not handy when you have to use this work-around with huge text parts.

Steps to reproduce :

    1. Write some text with the font: Liberation Serif 12
    1. Use a browser like Opera and cut and past some text inside yours
    1. Showing different fonts like : Verdana;Arial;Helvetica;Sans-serif for the paste text.
    1. Select whole text. Change Font into: Liberation Serif
    1. Select the Font-size box and check result