Don't really know how to call this; but what seems to happen:
- Have a POI layer active (an OSM one in the screenshot). Background layer doesn't seem to matter; both online and mbtiles behave the same
- Click somewhere on the background
- A little blue square appear where clicked - with the tagging corresponding to a 'selected' POI somewhere offscreen
I'm putting random in quotes because there does seem to be some logic to it. I can't discover what logic that would be though. It's definitely not the closest one, can be miles away. But it is often the same one

