It is not physically hard to shift. The lever seems to move to the proper place to re engage 2W but it stays in 4W until it eventually responds after repeated efforts.
Hard to get it to switch back to two wheel.
It easily goes into 4H or 4L. Then when I shift back to 2W position it does not come out of 4W. Eventually by backing and pulling forward and working the lever it has eventually gone back. It was perfect until just recently. Went from noproblem to...