Created attachment 126652 [details] pdf
Created attachment 126653 [details] Side by side
Not reproduced in v5.1.4.2 and 5.2.0.4 in Windows 7 or Ubuntu 16.04. Maybe this is an issue with font substitution. Could you give the font name and size you see in Draw for: -"29 April 2016", -"Please contact"? My observation in Windows is that when first clicking on the text, it says "Calibri", then after clicking out and back it's Liberation Serif (size is 18 and 12 respectively). In Linux it sometimes shows Calibri in italic (the missing font), other times Liberation Serif. Size is same as in Windows.
-"29 April 2016" and -"Please contact" said at one time calibri, now says Liberation Serif for most of the time when I select, sometimes says the first but changes to the last if I select again
Sizes are the same as you said, and calibri when shows is in Italic. Tested on Ubuntu gnome 16.04.1
Yep this also is a duplicate of bug 101220, of course on most Windows systems Calibri will be present so inability to extract the embedded fonts manifests on Linux boxes. *** This bug has been marked as a duplicate of bug 101220 ***