Would like but it has bugs – Adult Coloring Book Zentangle Review

Not sure what is happening or why. I have a new iPad Pro and use an Apple Pencil. I bought the pro package, That's when the problems began. One out of three pages I chose to color have a problem. Suddenly I will lose about half the colors I've already applied. When I try to correct I it won't let me. Half the colors stay different colors of grey. Tapping other colors do not let me correct by applying new color. As I have said this has happened several times. I have to start a new picture. REALLY annoying.
Review by KatarinaArt on Adult Coloring Book Zentangle.