Is the clip existing on the other side (latch side)
...pic... The channel the felt rides in is removable on the latch side.
As you can see it is not in the clip in my pic. I used an aftermarket felt and it was too short.
On the hindge side you might be able to attach a small tech screw in the area where the clip is missing inside the door.
...pic.... The window fallowing off the track sounds more like a regulator issue.
