Stepped Area Chart and color styling, how to get rid of vertical border line

[Carlos da Cunha e Silva]

Hi,

I want to have a graph that is color styled depending based on the value of the data. This can be achieved by editing the table and adding a color style to it. See https://jsfiddle.net/cdacunha71/1k1qb766/3/

But when I use this method I get this vertical border line that I want to avoid.

If you just use a color style by series, these vertical border lines are not introduced. See https://jsfiddle.net/cdacunha71/fqbtr7mn/1/

Can someone explain why this works like this or how I can avoid these vertical lines

Regards,

Carlos