The problem is when I scroll to the 2nd and 3rd product below, the sticky product area moves a little and the product heading is not show. This is unlike your demo page.
Please advise how to achieve the same sticky effect.
It works in the same way as on our demo but you see a bit different effect because your description block is very large. That is why the title is not visible when you scroll the page down.
Your site and product page work properly. `This is the way it should. When you scroll down the content goes up and disappears from the visible part of the screen.
The strange thing about this is that when I scroll down, the title does not stick. When I scroll back up from down, the whole description with title sticks!.
Could there be an error with your code? This is really not consistent!
I took your advice and tested it with a shorter description. Unfortunately, it is still the same case. Only when I delete all the description does the title stick. You will agree it does not make sense to have an empty product description. Seems like a bug to me.