I wonder if there's been any recent changes that would cause iOS version to hang like this. I have json that's 4k lines long, about 80 components stacked vertically, each with 2 stacked horizontally.
On opening the app it loads fine, but a pull to refresh hangs for ever, I have to kill the app. Nothing is showing in xcode to indicate what's wrong - the memory footprint is only 40mb. iPhone 7+ 128GB.
If I reduce the size of the json to half then refresh works fine and very quickly.