Bread boarded circuits have very high chances of loose connections.Your problem is intermittent. It may be a loose connection.

What about the power supply of the system? Your supply might have large ripple, and you can test it with a multimeter.

Turn on your multimeter to measure low voltage AC. Then measure the AC content of your DC power supply.It should be few mV. If more than 0.1, it might be the cause.

IA