Homeassistant Cast - Horizontal Stack not full width

I just got my Nest Hub and wanted to set up a dashboard for it.
On my PC everything looks fine, but on the Nest Hub the columns are squished together and not really usable.

Here is my Lovelace Configuration:
ui-lovelace.yaml

# Include external resources
resources:
  - url: /local/slider-entity-row.js
    type: js
  - url: /local/card-tools.js
    type: js
  - url: /local/layout-card.js
    type: js
  - url: /local/custom-lovelace/xiaomi-vacuum-card.js?v=2.2.1
    type: js
  - url: /local/mi_airpurifier/card.js
    type: module
  - url: /local/mini-graph-card-bundle.js?v=0.6.0
    type: module
  - url: /local/custom-lovelace/simple-thermostat.js?v=1
    type: module
#  - url: /local/custom-lovelace/compact-custom-header.js?v=0.0.1
#    type: module

title: Home
views:
  - title: Dashboard
    path: dashboard
    panel: true
    icon: mdi:view-dashboard
    cards: !include lovelace/dashboard.yaml
  - title: Nest Hub
    path: hub
    panel: true
    icon: mdi:tablet
    cards: !include lovelace/hub.yaml

Here is the dashboard config:

- type: horizontal-stack
  cards:
    - type: vertical-stack
      cards:
      - type: horizontal-stack
        cards:
        - type: custom:mini-graph-card
          entities:
            - sensor.living_temp
          line_color: '#E53935'
          hours_to_show: 24
          points_per_hour: 1
          animate: true
          hour24: true
          extrema: true
          name: Temperatur
          show:
            points: true
            fill: fade
            labels: true
        - type: custom:mini-graph-card
          entities:
            - sensor.living_hum
          line_color: '#00f8ff'
          hours_to_show: 24
          points_per_hour: 1
          animate: true
          hour24: true
          icon: mdi:water
          name: Luftfeuchtigkeit
          show:
            points: true
            fill: fade
            labels: true

      - type: custom:air-purifier-card
        entity: fan.luftreiniger

      - type: picture-glance
        title: Harmony
        entities:
          - switch.xbox_one
          - switch.xbox_360
          - switch.htpc
          - switch.tv
        state_image:
          "PowerOff": /local/images/power_off.jpg
          "Spielen - Xbox One": /local/images/xbox_one.jpg
          "Spielen - Xbox 360": /local/images/xbox_360.jpg
          "HTPC": /local/images/htpc.jpg
          "Fernsehen": /local/images/vu_zero.jpg
        entity: sensor.harmony_activity

    - type: vertical-stack
      cards:
      - type: entities
        title: Deckenlampe
        show_header_toggle: true
        tap_action:
            action: toggle
        entities:
          - type: custom:slider-entity-row
            entity: light.decke_1
          - type: custom:slider-entity-row
            entity: light.decke_2
          - type: custom:slider-entity-row
            entity: light.decke_3
          - type: custom:slider-entity-row
            entity: light.decke_4

      - type: entities
        title: Stehlampe
        show_header_toggle: true
        tap_action:
            action: toggle
        entities:
          - type: custom:slider-entity-row
            entity: light.stehlampe_1
            name: Stehlampe

      - type: entities
        title: Schrankbeleuchtung
        show_header_toggle: true
        entities:
          - type: custom:slider-entity-row
            entity: light.tv_lights
            name: Ambilight

      - type: entities
        title: Wandbeleuchtung
        tap_action:
            action: toggle
        entities:
          - type: custom:slider-entity-row
            entity: light.wandbeleuchtung
            name: Wandbeleuchtung
          - entity: input_number.wand_animation_speed
            name: Animationsgeschwindigkeit

This is how it look on my desktop

And on the Nest Hub in comparison

How are you getting this to appear on the Hub?

Can you put all the cards in a vertical stack and then use panel mode?