Apple Pencil Pro won't get charged properly

When I attach the ipad pencil pro pen to the tablet around 60-70%, it waits for 4-5 minutes to increase by 1%.Also, from 69% to 70%, it takes a long time.And when I plug it into a charger above 70, it takes a long time to fill up again.Is it normal?

[Re-Titled by Moderator]