Ok after a few weeks(!!) I found the answer:
In the follwoing line:
<div class="medium-3 columns show-for-medium" data-sticky-container>
<div class="sticky" data-sticky data-margin-top="0">
Having
data-margin-top="0"
Caused the logo to move everytime I navigated to another page. Removing this stopped the issue.
Hope it helps someone else!