I have an issue with a scrollbar on a form, that does not properly display as soon as I programmatically move the container.

On the form is one container object which could be higher than the form, and then the scrollbar appears at the right of the form to move the container up or down.

As soon as I change the top position of the container, sometimes the scrollbar disappears, or it does not refresh its position, so using the scrollbar it becomes impossible to move the container back to its original position.

I do not change the height of the container, only the top property. I also tried THIS.DRAW() on the form without success.