I had such label (let's say net1), with a netport, but I deleted it later on.
I still get the "This label is not connected with any pin" error message.
When I double click it, the schematics shows the location, but there is nothing there.
If I try to connect this location with a net, I get the dark circle, so there is something there, but I can't delete it, nor see it.
Any idea how to delete it?
            
                        
            
                                    
              
                Chrome
                  85.0.4183.121
                Windows
                  10
                                EasyEDA
                  6.4.7