I confirm the issue. See also https://issues.joomla.org/tracker/joomla-cms/13831

@ciar4n can you look at this? Looks like we have a wrong margin-left.

The problem here is two-fold..

1. Firstly Bootstrap 2.3 wells are not designed to contain a grid

2. The LESS compiler used in Joomla breaks the grid on smaller screen sizes (#13768). As this is within an iframe the same issues apply.

@ciar4n your Info belongs #13831?

This Issue here is the same as #13831
I closed #13831 as duplicate.

Ideally the compiler issue should be fixed which would also fix this issue. How best to do that is questionable. We could either fix the current compiler (seems unlikely) or replace the compiler. Failing that we can simply override the current compiled grid with a correct version. The later I can do however would be the least ideal solution as we would be duplicating CSS.

@ciar4n thanks for Info.

PR: #13845

@ciar4n thanks for your Work.