ApexCharts-card - issue with speed

Hi
I have started using ApexChars-card and it has been working fine. I then added another one with a sensor I made myself. And it brought my whole HA to a crawl. Refreshing the dashboard, just loading the sensor etc was extremely slow. I deleted the reference to my sensor and it went back to normal.

I assumed it was my sensor but it worked fine with a gauge and when I click on it to see the history it works perfectly.

laundry_power_used_not_free:
      friendly_name: 'Laundry Power NOT Free'
      unit_of_measurement: W
      device_class: power
      value_template: >-
        {% if states('sensor.is_power_free_time') | lower == 'false' %}
          {{ states('sensor.laundry_power_used') }}
        {% endif %}


  is_power_free_time:
      friendly_name: 'Is Power Free Time'
      value_template: >
        {% set t1 = now().hour %}
        {{ t1 >= 21 and t1 < 24 }} 

Any suggestions would be much appreciated

Have a read of this: