Page becomes unresponsive after closing a modal in iOS webkit, safari & chrome

• The issue is present in the latest release.
• I have searched the issues of this repository and believe that this is not a duplicate.

Current Behavior 😯

After closing a modal the screen becomes unresponsive to press/click events until the page is scrolled again. This is only an issue on iOS (simulators and real devices). It also only happens after you have scrolled down the page. See the video: https://photos.app.goo.gl/8GXMzb5iEUKC11jw9

Note, in the video it works as expected until I scroll down the page.

Expected Behavior 🤔

After closing a modal the page should respond to press/click events.

Steps to Reproduce 🕹

Steps:

1. Visit https://book.secretspa.co.uk/categories/Nails on an iPhone
2. Scroll down the page
3. Press a treatments "Book Now" button
4. Close the modal that opens
5. Try and press on another element
6. It doesn't always happen so I suggest trying a few times.

Context 🔦

I have tried to reproduce this in a codepen but it seemed to work as expected. I've inspected the DOM on the website in question when the issue happens and there's nothing I can see that is overlapping the view.

I understand this is a difficult bug to help with as I cannot provide a code pen example, however I wonder if anyone might be able to suggest why this is happening so I can hunt down the issue.

Your Environment 🌎

Start by reproducing the issue at https://book.secretspa.co.uk/categories/Nails on an iPhone: scroll down, open a treatment modal, close it, and test another element. Compare the behavior in iOS Safari and Chrome, repeating the sequence because the failure is intermittent; done means the page remains responsive after the modal closes.