So input_dim is a single feature of length seq_length? Is that the way to interpret it? That’s why the properly constructed model would show:
LSTMNet ( (lstm): LSTM(1, 128) (linear): Linear (128 -> 1) )
So the 1 in  (lstm): LSTM(1, 128) is not the size of the window (5) but instead the number of features? Features which have length of seq_length (5)?