has only one pin and Nets Wire has multiple names in Altium multi Sheet
In project options make these settings:

Add netlabels to the toplevel sheet:


Compile:



Please, use only 100mil schematic grids.  You will thank me later.

The modified design files can be downloaded from here (expires in 30 days):

https://www.dropbox.com/s/ov0x0fqlfopwl0h/main_with_mods.zip?dl=0