my 55PFL7606 has the newest Firmware.

My XBox360 is connected on HDMI3 and a device on the HomeScreen is created to switch to it.
Yesterday i noticed, that this "Device" or call it a "link" is gone, lost, deleted ...

When trying to create a new Device, i cannot select HDMI3. It is not there, just like it is occupied already.
I can select all Inputs which are free, like HDMI2, HDMi Side, VGA ... but no HDMI3.

I can switch to HDMi3 with "Source" on Remote Control.
But not on the Home Screen.

I tried to disconnect Power for 5 Minutes, and then retry - no use.

Please help.