The site sets "overflow: hidden" on body element, which by design blocks scrolling.  I think iOS Safari still does not support this and I suppose rottentomatoes only tested this filter flow on iOS.

We've shipped this behavior for years now and it had a lot of breakage at first, but it's a little surprising to still see a site with the problem.  Maybe we should reopen the interop discussion with Safari since it's causing us a few problems as well?

Ignoring overflow: hidden was necessary pre-"virtual viewport" since otherwise you couldn't pan around after pinch-zooming. Now that Safari is shipping that it should be easy for them to respect it. I can bring this up with Safari engineers at TPAC.

I've reached out to rottentomatoes via their chat support and twitter. The chat agent said they would forward it to the engineering team. 

I've tried reaching out to an individual directly that I found on github. Hopefully we might be able to make some progress on this.

The page behavior looks correct to me (don't remember if it's changed since I last looked). The page isn't scrollable but that appears intended, the filter dialog that pops up is meant to be modal. Dismissing the dialog allows the page to scroll again. In fact, Safari looks broken here as the page scrolls behind the modal dialog. In this case, user experience isn't broken by the difference and it's a known issue so I'm going to close this.

Safari now supports the visual viewport pinch-zoom model so I think this is a tractable bug for them now - I'll try to follow up to get them to fix it. 

FYI: https://bugs.webkit.org/show_bug.cgi?id=153852 is the WebKit bug - it looks like they tried it but reverted a little over a year ago. I pinged the thread to see if anything's changed. Perhaps we could gather some data and see if it paints a more compelling picture - anecdotally, I haven't seen many bugs like this in the last few years (it's a pretty obvious bug when the page doesn't scroll...).