I have a similar problem intermittantly, usually hot days.
When this happens, I have the roof go forward first(Push the button forward) and then have it push back. This seems to retract the rear of the glass and frame enough to get past the tight spot.
The real fix is probably to adjust the window or lubricate the rubber weather seal with some silicone grease. There is a special grease for weather seals. I haven't tried either fix because I am lazy or don't want to get grease streaks on the paint when I hand wash.
Good Luck,
Jim Henderson