Why is my RMSE and MAE is scaled?

https://colab.research.google.com/drive/15TM5v-TxlPclC6gm0_gOkJX7r6mQo1_F?usp=sharing

pls help me (pls if you have time go through my code).. I'm not from ML background just tryna do a project, in the case of hybrid model my MAE and RMSE is not scaled (first line of code) but in Stacked model (2nd line of code) its scaled how to stop it from scaling and also if you can give me any tip to how can i make my model ft predict better for test data ex_4 (first plot) that would be soo helpful..