If Cox is bench-checking and refurbishing returned equipment, leadership needs to assess your process because it is definitely broken.
Cox issued me a cable box (Rovi) and its remote control had a section of non-responsive buttons. This unit could not have been refurbished.
Cox also issued me a cable-box with a dead HDMI port. Straight out-of-the-box and zero output signal. This unit could not have been refurbished.
Cox issued me a telephone modem with its power receptacle broken from and dangling within its chassis. This unit could not have been refurbished.
Either Cox is issuing equipment from its defect pile or you're not performing acceptance inspections.
Cox issued the OP 3 difference boxes with 3 different defects...ranging from power-on, to remote control, to dead screen...and Cox blames the OP's wiring. As a further insult, Cox tries to push Complete Care knowing no technicians will enter houses due to COVID.
OP will need to exchange the Mini Box...again...because there must be at least 1 operational box left at the Store.