1. I left it open for a while before closing and it worked.
2. The problem is that it was animating based on keyframes and classes. This worked previously, because I added the class to the keyframe in the CSS menu as a new class, and it changed the opacity property.
3. Since I relied on the animate classes, it wasn't working because I was applying the opacity in the class. Previously, this worked in conjunction with keyframes.
4. Doing according to your indication I was able to change the opacity of the element and easing properties.
Thanks for the answers,
Brendo Marinho