Hello
I experienced this issue on iPad Safari as well (not iPhone, iOS version doesn't really matter based on my quick testing). The issue is probably on the <div style="background-color: rgb(255, 255, 255); border: 1px solid rgb(204, 204, 204); box-shadow: rgba(0, 0, 0, 0.2) 2px 2px 3px; position: absolute; left: 66px; top: 899.5px; transition: visibility 0s linear 0s, opacity 0.3s linear; opacity: 1; visibility: visible; z-index: 2000000000;"></div> .
This <div> and its contents are covering the form / page and this explains why a user cannot interact with the form probably after ticking images from this overlay.
Hope my observation is useful!