I have imported elevation contour shapefiles, divided by 5 regions of North Carolina, into ArcGIS Pro. I have merged several smaller blocks of this data already to create these regions, and now I want to merge the regions to provide a statewide contour file. When I run the merge tool in ArcGIS Pro, the program will not draw certain parts of the final product. Parts of the state are left out. No matter how I try to configure my regions, it always leaves parts out. Any ideas as to what is causing this?