I have just tried to reproduce your issue but I was unsuccessful. I have updated my RUT9 with the RUT9_R_00.07.00 firmware version and created a simple test group (included only a single number). I have changed the status message configuration to be available only to my test group and to require no authorization. After sending a simple status message to the router, I have received a correct reply. I would like to ask if you could try to reset your router to the factory default configuration and try to configure everything once again. I do believe that something went wrong with the upgrade process and keep settings from older firmware.