Issue with Dropdown & numeric entry field on Perspective Pop Up

I’ve having an issue in 8.0.17 which is similar but not 100% the same as
When I open a pop up (using system.perspective.openPopup) with a drop down or numeric input component I am unable to select anything in either component. If I navigate to the page instead (using system.perspective.navigate), then no issue is seen.

Support ticket #5472 created

This is a known issue when the popup size exceeds the size of the viewable area of the browser.