Magento 2.3.4 – Shipment Status is always empty

i am using Magento 2.3.4 and i see in the sales_shipment table that there is a field called shipment status. This field is empty, but if i look in the Model i saw that there is default value “New”. So, how does this field work? – For my requirements i need a state at the shimpment but i do not get it work!

Any ideas?

Best Andre