I got only 54% in LABS even though all my answers are correct. Why?

I finished Introduction part and answered all the questions correctly, but i don’t know why the grade is only 54%.

You are still in the middle of the course (26 of 78 completed)
I think you completed first chapter(1st week)
As you progress through the course score keeps changing
You may have to wait for next chapters to open
Check upcoming chapters(most likely they are in disabled state)

That make sense. Thank you so much for your response. I really appreciate it.