Red HAN light flashing on electricity console

On the electricity box in my cupboard there is a red flashing light. There are three lights WAN (green constant light), HAN (red flashing light) and PWR (green constant light). I’ve only just noticed this when reading the meter for a reading submission. Can’t really say how long it has been like that. It is a Trilliant box that leads directly to a metal electricity box which I presume is the mains supply - model no. SEAP-2000-V. It’s not a smart meter. Does anyone know if this is normal???