Render Error With Mushroom Lock Card And Middle Class

[hdprice]

The middle class doesn't render the vertical border correctly when used with the Mushroom Lock Card. The border is rendered with curved corners on the left (see image). Here's the YAML I'm using.

          - type: custom:mushroom-lock-card
            entity: lock.front_door_halo
            name: Main Airlock
            icon: mdi:door-sliding
            card_mod:
              class: middle

Any help you can give would be great!

Thanks for an amazing HA Theme!