The network output matches the target curve but with a different scale

Im passing yesterday’s groundwater level as input and getting today’s groundwater level as an output. there is one hidden layer with two nodes, im using ReLU for the hidden layer and Sigmoid for the output layer. I normalized both the input and the output.
what I am trying to do here is to test if the model actually works as this is the my first model ever, and it must converge because I am using the same data for input and output except that the output is the input shifted one day ahead and with groundwater level; we are talking about centimeters difference between today and yesterday. so the data is time series water level, the same series is shifted one day and used as an output.