Borders now appearing after 2024.1.2 update

Good morning all,
After the lastest update, I’m seeing borders where I had previously had none for stack-in cards. For example, one of my cards shown below had no cards.

type: custom:stack-in-card
mode: vertical
cards:
  - type: horizontal-stack
    style: |
      ha-card {
        border: none;
        align-items: center;
      }
    cards:
      - show_current: true
        show_forecast: false
        type: weather-forecast
        style: |
          ha-card {
            border: none;
          }
        entity: weather.openweathermap
      - type: conditional
        style: |
          ha-card {
            border: none;
          }
        conditions:
          - entity: binary_sensor.moonrise
            state: 'on'
        card:
          type: custom:mushroom-template-card
          style: |
            ha-card {
              border: none;
              align-items: center;
            }
          primary: Moon phase
          secondary: '{{ states(''sensor.moon_phase'') | replace(''_'','' '') | capitalize}}'
          picture: |-
            {% if is_state('sensor.moon_phase', 'new_moon') %}
            /local/images/MoonPhases/new_moon.png
            {% elif is_state('sensor.moon_phase', 'waxing_crescent') %}
            /local/images/MoonPhases/waning_crescent.png
            {% elif is_state('sensor.moon_phase', 'first_quarter') %}
            /local/images/MoonPhases/first_quarter.png
            {% elif is_state('sensor.moon_phase', 'waxing_gibbous') %}
            /local/images/MoonPhases/waxing_gibbous.png
            {% elif is_state('sensor.moon_phase', 'full_moon') %}
            /local/images/MoonPhases/full_moon.png
            {% elif is_state('sensor.moon_phase', 'waning_gibbous') %}
            /local/images/MoonPhases/waning_gibbous.png
            {% elif is_state('sensor.moon_phase', 'last_quarter') %}
            /local/images/MoonPhases/last_quarter.png
            {% elif is_state('sensor.moon_phase', 'waning_crescent') %}
            /local/images/MoonPhases/waning_crescent.png
            {% endif %}
          fill_container: true
          multiline_secondary: false
          tap_action:
            action: none
          hold_action:
            action: none
          double_tap_action:
            action: none
  - type: horizontal-stack
    style: |
      ha-card {
        border: none;
        align-items: center;
      }
    cards:
      - type: conditional
        conditions:
          - entity: sun.sun
            state: below_horizon
        card:
          type: custom:mushroom-template-card
          style: |
            ha-card {
              border: none;
              align-items: center;
            }
          primary: >-
            {% set sunrise = state_attr('sun.sun', 'next_rising') | as_datetime
            | as_local %}
              Sunrise is {{ 'today' if sunrise.date() == now().date() else 'tomorrow' }} at
          secondary: '  {{ (state_attr(''sun.sun'', ''next_rising'')|as_datetime|as_local).strftime(''%-I:%M %p'') }}'
          icon: ''
          tap_action:
            action: none
          hold_action:
            action: none
          double_tap_action:
            action: none
          entity: sensor.nextsunrise
      - type: conditional
        conditions:
          - entity: sun.sun
            state: above_horizon
        card:
          type: custom:mushroom-template-card
          style: |
            ha-card {
              border: none;
              align-items: center;
            }
          primary: >-
            {% set sunset = state_attr('sun.sun', 'next_setting') | as_datetime
            | as_local %}

            Sunset is {{ 'today' if sunset.date() == now().date() else
            'tomorrow' }} at
          secondary: >-
            {{ (state_attr('sun.sun',
            'next_setting')|as_datetime|as_local).strftime('%-I:%M %p') }}
          icon: ''
          tap_action:
            action: none
          hold_action:
            action: none
          double_tap_action:
            action: none
      - type: conditional
        conditions:
          - entity: binary_sensor.moonrise
            state: 'on'
        card:
          type: custom:mushroom-entity-card
          style: |
            ha-card {
              border: none;
              align-items: center;
            }
          entity: sensor.astroweather_moon_next_setting
          icon_type: none
          name: Next moonset
          tap_action:
            action: none
          hold_action:
            action: none
          double_tap_action:
            action: none
      - type: conditional
        conditions:
          - entity: binary_sensor.moonrise
            state: 'off'
        card:
          type: custom:mushroom-entity-card
          style: |
            ha-card {
              border: none;
              align-items: center;
            }
          entity: sensor.astroweather_moon_next_rising
          name: Next Moonrise
          icon_type: none
          tap_action:
            action: none
          hold_action:
            action: none
          double_tap_action:
            action: none

The cross below in the middle of the card was previously not there.

image

This is happening on many of my cards where the style → ha-card → border: none is applied.

Does anybody know what changed or how to correct this?

Your card_mod notation is invalid.
Read the latest release notes for the card_mod integration.

What specifically is invalid? All of this worked until the 2024.1.2 update.

No, it worked untill the last card_mod update.
Syntax has changed.