Anita, you've been answering lots of threads in the community forums so I'm going to give you a longer explanation (/ some background) since you may encounter someone in the community forums with a similar issue.
The html markup in the default BP theme has not had any substantial changes in the last 3 years. It has not had any changes in the last 18 months. Other than applying some needed changes to the BP index pages so that the markup works with Genesis, all versions of GC template have used the same markup as the default theme.
In the last 2 years I have not had to do any fixes for structural issues (html markup/css affecting layout). All instances of layout being messed up have been a result of a handful of issues:
95% - the BP template pack templates are installed in the child theme - that's the reason that the installation instructions start with removing those templates
4+% - the site is using a plugin that includes it's own templates (which have the default theme/template pack markup) vs using the plugin templates in the child theme
<1% - circa BP 1.2 there were a couple plugins that relied on CSS in the BP default theme (IIRC css for blog comments) & they created the same problem with any custom theme. I don't know whether those plugins have been maintained/improved, etc.
To your particular issue-
If the screenshot above is from a core BP screen then you need to go into your web account/FTP and remove the BP template pack templates from your child theme.
If it's from a screen added by a plugin then you should contact the plugin author to ask about the templates being used for that screen.