Electric window not seating correctly

Have read a few posts referring to electric windows not going up properly. I too have this issue.

Have stripped it down and tried silicon spray which improved the action but it still reqs a bit of help for it to go all the way up!

The front of the glass seats ok its just the door handle end at the top. Any help greatly appreciated.
Update - its working again! I moved the glass as far back in the holders as possible. Im assuming the plastic in lay around the window frame has gone brittle in places and has moved. The silicon spray helped too. Cheers