There are a lot of nodes on the end of your crosshairs, and if your coastline is more intricate than the one Ralf was using as an example in that video it will behave as you describe until it is pasted.

Perhaps an easier thing to do, rather than trying to move all those nodes around until you can get the cursor to the corner, is to type the paste origin in on your keyboard and hit return. That's 0,0 (zero comma zero).

Then right click to clear the crosshairs before you accidentally paste it a second time.

@Royal Scribe The HW overland style is included with the core app these days.

I made an "Effluent Scum" fill you can use in various different scenarios?

I think Herwin gradually moved on to photography more than fantasy art over the years, so while it would be nice to see these styles expanded I think it's probably not that likely to happen.

If you can't get rid of the layer is it really worth scrapping everything to start all over again?

Layers aren't anywhere near as important as sheets. Most of the time I completely ignore them.