Atlas Node Accessible w/ no Other Completed Connected Node + Changing Atlas Layout

finished a map (as image demonstrates my player pin location), and other two unconnected nodes became accessible even without any other connected map to them being completed.


zoomed in:


zoomed out:


I tried accessing one of them, and was able to run the map and complete it as a normal accessible node that had completed nodes.
When I finished the map and accessed my atlas again, the whole layout changed for that region, as show below.