[Pilotdave]

Not saying this is happening to you, but maybe....

I had issues with the window glass in my A400 doors. They both were really hard to raise or lower. I removed the felt tracks and found that the adhesive that glued two layers together had soaked through the felt so that the track was sticking to the glass. Affected both tracks in both doors. Might be possible that you have a spot in your tracks on the passenger door where that's happening.