Crestle showing that I have used GPU, although I haven't

Hello everyone, this is Rahul from India. So, I started with the 1st video of Part 1 using Crestle today. After using Crestle for about 4 hours, I am sure I must have turned off both Crestle and Jupyter Notebook. But now, I found out that my usage has been as follows :
crestle

How is this even possible ? Was Crestle running the GPU even after I had shut down my laptop ? But I specifically remember having turned off the GPU… Has anyone else faced this problem ?