Card Borders showing on mobile but not on web

Hi,

I have the following stack-in-a-card that shows the borders between the individual cards in the mobile version but on web it works correctly. Does anybody know how to hide them in the mobile version?

image

- cards:

  - cards:

    - entity: climate.office_ac

      icon: mdi:hvac

      layout: horizontal

      name: A/C

      primary_info: name

      secondary_info: state

      show_temperature_control: true

      type: custom:mushroom-climate-card

    - entity: climate.office_ac

      hvac_modes:

      - heat

      - cool

      - dry

      - 'off'

      icon_type: none

      layout: horizontal

      primary_info: none

      secondary_info: none

      show_temperature_control: false

      type: custom:mushroom-climate-card

    type: vertical-stack

  - cards:

    - entity: sensor.lumi_lumi_weather_temperature_4

      icon_color: red

      name: Temperature

      primary_info: state

      secondary_info: name

      type: custom:mushroom-entity-card

    - entity: sensor.lumi_lumi_weather_humidity_4

      icon: mdi:thermometer-water

      name: Humidity

      primary_info: state

      secondary_info: name

      type: custom:mushroom-entity-card

    columns: 2

    square: false

    type: grid

  keep:

    background: false

    border_radius: false

    box_shadow: false

    margin: false

  title: Climate

  type: custom:stack-in-card

I have background, border_radius, box_shadow and margin set to false.

Thank you in advance.