I have placed a number of embedded facebook posts on my clients site. Everytime I try to test the spacing, it is off and different on chrome desktop and that of mobile desktop, same thing with the spacing in mobile version.
I will include the link below, Right now it is fine because I went in and manually moved everyone to space them properly. The issue is vertical spacing. I am using v19 and do not think if this is a bug that xara will spend the time and effort to fix it.
It seems every issue with xara has a way around it by doing it differently therefore eliminating the actual cause and problem that originated it.

https://www.clearsoundhearing.ca/articles.htm