I have come upon an interesting problem with my Arduino; I build a circuit and write code that compiles OK, however it will not run on any of the computers on my router - 4 different computers on my home network. Yet, if I take the identical setup to a friend's home, it runs flawlessly. This happens whether the Arduino is a Genuino or a Chinese clone.
The problem has just started . Previous builds ran fine but something has entered my home network that interferes with the process.
Has anyone out there encountered this problem?