There seems to be something funny or at least counter-intuitive going on with the initial data from sister search. See:
From the desktop numbers, it seems like desktop search has 10x the 'results' page opens as mobile search. This makes sense and, as @debt mentioned, Sister search is below the fold on mobile, however, the traffic being referred from mobile is almost double. On other projects, I have found
that when intuition and the data disagree, it is often because there is something glitchy going on.
Can you take a look?