Weird placement of objects

I’m trying to create a new airport / aerodrome and when I click to insert an object (polygon, taxiway point, apron…) in a specific location, the object is randomly placed far from its position (generally on the upper left side of the screen, see the picture).
Why is doing this?

Same here. The dev mode user interface is absolutely horrible. It’s left over from the 8-bit version. I see the same off-screen placement when “adding” the first point of polygons and aprons and also when “clicking” whole objects into a scenery. Just dumb programming.

Some dev should offer a better user experience but I suspect the issue there is that the sim doesn’t provide enough external interface to do this properly.

I absolutely love the sim side of MSFS2020 and feel that I’ve gotten more than my money’s worth there but the dev side of things is simply off-putting. It seems as though some parts of the sim are but a glimpse of what’s possible and always out of reach.