Radio interference

Has anyone experienced radio interference while controller is booted up?
when I listen to AM radio, it sounds OK until I boot the controller. The interference does not seem to affect FM radio.
Is there a filter that can be installed or do I maybe have a defective controller.

AM (Amplitude Modulation) radio is very susceptible to switching noise from power supplies and computers. Whereas FM (Frequency Modulation) is very tolerant. Most probably the noise from your controller is typical and indicates the RF shielding is lacking. A line filter could be added to limit the RF radiation from the power cord but not much probably can be done for the main chassis.

Since the controller has an antenna for the wifi inside it there can’t be much for shielding.