color not filled inside the vector

[shivani bhati]

when I am doing expand and appearance on my brushes stroke and merge then it will not fill full color inside the vector. I am practicing from this video https://www.youtube.com/watch?v=uLW4Wi8BAnk&t=1263s and doing the same steps but at last, the color disappears inside the vector. please help me out. 

Thank you

[Monika Gause]

Please show a screenshot of your artwork that shows the problem.

Please tell us your exact steps.