Scale of data matters when it comes to training a model quickly. This goes back to course 1 week 1 (house price prediction) that asks you to take this into consideration. Here’s another post that iterates on the importance of scale of data.
Please look at course 4 week 1 material on how to remove trend and seasonality to make time series stationary. This step is done before you take further steps for rescaling the dataset based on parameters learnt from the training split.
Do look at these posts as well: