Rollershutter status shows undefined

Hi,

I have some rollershutters that are controlled via a widget. There is a group-control and individual control. The group has an aggregate function with AVG. Now, with the group, it shows the percentage correct on the widget but with the single shutter control is shows undefined.
Schermafbeelding 2021-10-26 om 15.50.38
No matter if I use a meta state description %d or %.0f, it keeps showing undefined. If I were to put state instead of displayState I get, eg, 49.000000000% so I use the display part to get rid of the decimal 00.

YAML:

- component: f7-block
      config:
        style:
          position: absolute
          bottom: -35px
          left: 16px
          flex-direction: row
      slots:
        default:
          - component: Label
            config:
              text: "=Number(items[props.item].state) < 2 ? 'Open' : Number(items[props.item].state) > 98 ? 'Dicht' : items[props.item].displayState + '%'"
              style:
                font-size: 12px
                margin-left: 0px
                margin-top: 0px

Any ideas anyone as to why this is happening?