I've noticed lots of students who fly wing down in the early part of their training.
Students in the left seat would tend to fly R wing low, and those in the right seat (eg trainee instructors) would fly L wing low
Seems to be related to the centerline offset of the seats plus trying to use the cowl/visible sky as the reference for horizontal. They appeared to be trying to achieve an equal ground/sky field of view as they looked from one side to the other.
I suspect that the uneven view from the left or right seat, compared to a centre line seat position is to blame.
In a similar vein is students trying to align heading by using the centre of the cowling instead of a point directly in front of themselves. Again, this is with the offset seating.
One fellow was so adamant that he was flying wings level & heading accurately that I had to line us up dead straight on the runway with him on the centreline then mark the windscreen where a the end of the runways 'touched' + a spot that was aligned with the RWY end centreline.
After that, go flying & see the difference.
I think that if instructors allow students to develop these habits they become ingrained as their primary 'reference' instead the correct one(s)