I had a Robbins canvas top with a zippered glass window on my ex 99 miata and I could not open the top unless I first unzipped the glass window, otherwise the top would get stuck at the last 30% going down.

that was such a royal pain in the ass to do each time to open and close the top, especially with a double diagonal roll bar....

maybe the previous owner used NA frame or something....?

Did you notice if the rearward hoop was getting stuck, or was it sliding normally towards the second hoop?

it had nothing to do with the roll bar, it's was like that even before I installed the roll bar. The top simply would not fold all the way without first unzipping the window. I always thought it was a stupid top design

Oh i meant the hoop of the soft top. Not sure what the proper term is. My oem soft top gets stuck at before the bottom if the two hoops dont meet. I am now in the habit of just pushing the hoops together as I let the top fall.

oh the rear hop of the soft top frame, maybe mine was getting stuck there, not sure, I always thought it was a feature of the zipper glass top that I have to unzip it before opening the top, but could have been the rear hop getting stuck...

don't have that car anymore to check this theory

vinyl with zippered glass on my NA. The majority of the time my glass is down. Harddog made a double diagonal bar at some point that works with it. They probably still do.