Multiple chart lines from single array

[E1cid]

@becsL

 [msg.payload[0].map(obj => {return {x: obj.x, y: obj.y}})],
            [msg.payload[1].map(obj => {return {x: obj.x, y: obj.y}})],
            [msg.payload[2].map(obj => {return {x: obj.x, y: obj.y}})],
            [msg.payload[3].map(obj => {return {x: obj.x, y: obj.y}})]

You are adding an extra [ ] around your map arrays, try removing them.
e.g.

  msg.payload[1].map(obj => {return {x: obj.x, y: obj.y}}),