Fill Bucket Grease Pencil not working well

Hi dear community,

This is a question for those who use Grease Pencil! I am new using this 2D tool and getting use to it.
I am drawing shapes and when I try to fill them with the bucket it just don’t do that and when it fills a shape starts making crazy things when I try to fill a second shape. Is like it is not recognizing the outlines I’ve been creating and therefore not filling when I click on the viewport to fill the area of the shapes with any material.
I am using a Wacom Intous tablet and Blender version 3.5.1
I created 2 layer: 1 for outline and 1 for fills. Also created 2 material colors 1 for strokes and 1 for fills.

Appreciate all the help you could give me with this issue I’m having!

Here is a picture for you to understand: