Can anyone point me in the right place to start looking re an unusual power window problem?

The front passenger window on my 2000 CL (215) will drop down however when I try to close it using either the drivers side button for that window or the button actually on that door, the window will raise roughly half way and then stop and power back down an inch or so as if stuck.

It will do this each time I press either button, raise a little, stop and then lower a little. It may then decide to close fully on another attempt. Also if I switch the ignition off and back on then both switches, more often than not, close the window fully.

I've tried silicone spray on the rubbers wondering if it was sticking and treating it as an obstruction. I thought it may be the switch, but both switches for that window are doing the same, which would be unlikely.

It is no better if I try and close it with the rear quarter-light window open.

The drivers side window works but is slow.

Any ideas would be appreciated as I'm now stuck for what to look at next.

Thanks