Automatic layout doesn't work

Checklist:

• [ X ] I updated to the latest version available
• [ X ] I cleared the cache of my browser

Release with the issue: 1.2.0

Last working release (if known):

Browser and Operating System: Win10x64 Firefox 81.0.1

Description of problem:

Found a problem with config-template-card. Two or more cards are not distributed properly on the screen - all of them are placed in one column.

How to reproduce:

1. Add Speedtest integration.
2. Create an empty tab.
3. Add a new card:

type: 'custom:config-template-card'
entities:
  - sensor.speedtest_download
  - sensor.speedtest_upload
  - sensor.speedtest_ping
card:
  type: vertical-stack
  cards:
    - type: history-graph
      entities:
        - entity: sensor.speedtest_download
      hours_to_show: 24
    - type: history-graph
      entities:
        - entity: sensor.speedtest_upload
      hours_to_show: 24
    - type: history-graph
      entities:
        - entity: sensor.speedtest_ping
      hours_to_show: 2

1. The created card is like this: https://community-assets.home-assistant.io/original/3X/f/4/f400502463965a9d1875027ed469efee6999dfa8.jpeg

2. Then duplicate this card. Two…three cards are enough to see the issue. All cards are placed in one column.

Note, in this example there is no “variables” section - my actual code was like this:

...
variables:
  - 'states[''input_select.graph_hours_to_show_speedtest'']'
...
card:
  type: vertical-stack
  cards:
    - type: history-graph
      entities:
        - entity: sensor.speedtest_download
      hours_to_show: '${vars[0].state}'

I excluded that variable just to simplify the case.

Javascript errors shown in the web inspector (if applicable):

Additional information:

[ildar170975]

I managed to bypass the issue by using custom:layout-card with vertical-layout and layout-break.

[QbaF]

The bypass do works. It could be temporary solution.