Machine translation.
Since I could not solve the problem with the other methods, I will note my solution.
I do not recommend this method because I do not understand the logic. If you do this, please make a backup.
In line 984 of input_handler.gd, replace active in active_location.descript and active_location.classname with selected, respectively.
Next, in ExplorationModule.gd, at line 2152 and below, replace all selected_area with active_area.
Finally, rewrite the selected_area in line 893 of InteractiveMessageModuleAnimated.gd to active_area so that dungeons can be purchased.