Do this as an experiment, see if you will notice this issue. Take a PCB design that has lots of resistors, and in the schematic, change all the resistor numbers.  Then update the PCB.  You will see a net error for every one of them, of course, because the net name no longer matches the part. I fix this by changing the name of the net in its attribute menu.  But,you will also get 1 or 2 net errors that don't make sense.  The only way to fix is to delete the net and rewire it.