Same problem on many Cessna high-wing singles. They have tried to place
the little, forward-facing vent just behind the strut, to minimize the
slight static pressure that develops in flight, but you'll still have a
faster draw from one side. In my experience, newer models are no better.
There are literally dozens of articles on the subject, and as many
proposals for fixes. Some of these are probably good, and you should do
some internet research if this is bothering you. My own fix is simply to
switch to right tank only once I'm in cruise, and manage the disparity
from there. Back to both, of course, in the pre-land checklist.

GF