Alpine MRP-F240

My Alpine mrp f240 amp, has no audio when the car engine shuts off and turns back on. The power light is on, 12.8-14.5 volts is at the remote and battery terminals. When this happens I have to disconnect the B+ from the amp for a few seconds and then reconnect, and the audio comes back. Has to be done with the radio on. Please help as this is sometimes frustrating to do, Everytime the car has to be started