This is reproduced on iPadOs 13.1.3 with DTTG 2.7.4.
It’s best illustrated in my video clip (https://streamable.com/9l8d3).
- When using the Share extension, there is a dark grey background dim behind the pop-up window.
- When tapping the “back” button on the top left of the pop-up window, the extension freezes.
Both are 100% reproducible across all host apps.