I was trying to edit my user profile page at https://www.mediawiki.org/wiki/User:01tonythomas , using the VisualEditor template edit view, and removed a line from the 'Contact Me' section.
Once I click on save, I see the entire page mis-aligned, with the following change in Gerrit history -
The template then had its TemplateData altered to specify layout as 'block' instead of unset, after which the same edit serialised as expected: