It is not uncommon for our windows to face resistance at the upper part of their travel.
I believe it is basically a mismatch between the curvature of the glass and the curvature of the window tracks.
If you haven’t already, I would suggest you spray a silicone lubricant into the vertical window channels. I have seen some improvement using this approach.
do NOT use a petroleum-based lubricant such as WD-40
Larry