Apexchart card not filling full card in layout-card

Hey there, I am having a dashboard with layout card grid. In this dashboard I have a card with apexchart-card. My problem is, the apexchart card does not use the available space. The width seem to be calculated by apexcharts library and I would like to know, why it’s not full width and what I can do.

Here is the relevant part of my dashboard

      - type: custom:apexcharts-card
          grid-area: apex
        graph_span: 1d
          start: day
          - entity: sensor.power_today_production
            type: column
              type: sum
              period: hour
              duration: 1h
              start_with_last: true
              func: diff
    type: custom:grid-layout
    subview: false
      grid-template-columns: repeat(6, auto)
      grid-template-areas: |
        "weather1 weather1 weather1 weather2 weather2 weather2"
        "total now now now list list"
        "today now now now list list"
        "grid now now now list list"
        "apex . . . . ."

This is how it looks

Do you have an idea what I can do to fix this?
Thanks in advance