I have Bermuda grass on my lawn. I built a fence around my backyard
about three years ago. Since then the grass in the left fence corner is
gradually disappearing (the spot is enlarging from the fence post
toward the house). Currently, there is a spot about 10' x 10' which
is completely barren. I also have a tree in that corner but I have two
other trees in the backyard and the grass there is just fine.

What may be causing the Bermuda grass to dislike the fence? More
importantly, what could be done to reverse the process?