Hifonics brz2400.1

Hi I have a hifonics Brutus 2400.1 amp my problem is when I turn my truck on the radio and amp turn on fine and plays fine but when I turn truck off everything shuts off like it’s supposed too but after a few minutes sometimes more the protect light blinks once then the power light comes on and stays on. If anyone has any ideas on what this could be I’d greatly appreciate the help