I don't know if anyone has encountered this issue. Tile placement works fine, but I believe there's a bug. At the initial location, the red box marker is in the right place. However, as I progressed further and further, the red box moved farther and farther away from me. After I had placed over 60 km of terrain, the red box ended up very far away. Regardless of its location, the tiles were being placed above where I was.
Thanks for the suggestion! When you mentioned restarting the editor, did you mean simply closing and reopening it, or is there a specific reset function within the editor that I should use?