Consumption at night time
I

recently bought the Sunsynk powerlynk all in one 3.6kw
Hybrid inverter. We are fully expecting off grid therefore we only received energy from the solar panels. At night time we try not use less energy as possible as we aim to maintain 80% and above SOC but what I have noticed is that we consume 4w until the morning which drains the battery to about 72% SOC which is not ideal and I can also see that we are discharging 23w to cover the 4w. The only item we have plugged in at night is the router which is connected to the data logger and that’s it.
What do you suggest we do should we switch off the inverter at night and switch it on in the morning to save the energy or there is a setting to control the discharge? We want to make sure that the SOC stays above 80%

You are misunderstanding what "80% DoD" means. It means you can use 80% of rated capacity (discharge it down to 20%) and still have rated number of cycles (typically 6000 cycles until battery degrades to 80% of new capacity, that's 16 years of daily charge/discharge).