So I was trying to start a dig on a new playthrough and I messed up my ladder when I placed them on top of the dig point. So i selected the cancel tool and tied to clear just the misplaced stairs, but the dig point behind the stairs also got cleared.
What I think is happening is when you place a build plan, if there is a dig point behind it it's getting replaced by the build plan (since building will clear that section out anyways) so when you clear said build plan even though there was a dig point behind it originally the dig point actually isn't there anymore? What should happen is if that's how it's working it should retoggle the dig sprite after clearing a misplaced build plan.
Edit: After testing my theory above, I used the clear tool while only having the building ticked for clearing and i selected the complete dig area with my ladders and the ladders did get removed and the original dig point is definitely gone.
1. Add dig point 2. Place ladder on top of a dig site 3. Hit "C" to open up the clear tool and select "Buildings" only from the options box (ps: can we have a way to quickly flip through options? with like arrow keys or something when the window is open) 4. Select the complete dig area including the section with the misplaced ladder 5. The ladder area gets removed & the dig point is also removed, since I'm assuming the placed ladder completely override the original dig plan when something else is placed on top of it.