placing shortcodes inside tabs

Hello again support !

Still working away on a site with my first purchase of enfold.

I am working on the services page.
And have set up tabs on the page for services.
The content inside these tabs, I want to split into two 1/2s. I have done this by pasting in shortcodes and adding content… no issue there.

However… my issue is this:

In the very first tab, the content inside the tab is fine – and inline with top of the available space in that tab.
BUT, in every single following tab, although the content appears as it should (in two halves) the top margin of content is about 40px below where it should appear (in line with first tabs content).

I have gone through forum, installed debug editor, gone through every single line of code, checked for spaces, etc etc….
but to no avail… I have spent hours on this… and it’s driving me nuts.

The shortcodes used inside every tab should be identical (as for layout they are all copies of the first one… it’s only the text or url to image that is changed).

Am I missing something completely obvious is setting up layout??
I thought it may have something to do with [av_one_half first] ?
I tried putting a colour container into a tab, and then two 1/2s into that… but that did not work at all, and wrecked layout of whole page.

Pls help.. need to get this site live very soon.

Thanks again
O.