AC Input current limit is set to 6A. An AC current sensor is connected. Power Assist is activated. Until yesterday it worked without problems for months.
As long as AC load is above this, everything works. As soon as a larger consumer is removed and the AC load falls below 6A, a loud hum is heard and a negative value appears in the VRM dashboard at AC Input (thus battery charge is released into the mains). The solution with the "headphone trick" I have already found on the net and tried. Plug a 3.5 mm headphone cable a few times into the socket "AC Input Sensor" on the multiplus II and the short circuit is solved. However, the error (short circuit at the AC Current Sensor) comes again and again the trick must be used.
How can the problem be solved permanently?