Network unbalanced for time step 0


I get the error "Network Unbalanced" for my model. I checked the validation of my model and no error was found. None of the "common causes" match my model either. However, my flow seems to converge to a value for all the other time steps (see below). Can I assume this value (1,547.34) is correct? And how can I ask the system to show another time step than hour 0 in the properties?