Looks like the power supply is still making noise. Turning off the back of the camera removes the noise because it reduces the current consumed. Also, the noise removes power through the lighter or the inclusion of this wire in the second connector.
Ferrit filters don't seem to help. Not on the camera or on the power supply.
Tell me, please, how to overcome the noise in the power supply.
Maybe there are other good power supplies? Or embed an assistant in the scheme? Or parallel another HK3 to put?