Why is my computed property doesn't get updated in Vue?

This should be easy, but I can't find what I'm doing wrong. The button should only be enabled when all the checkboxes are checked, but the change doesn't propagate. In fact buttonDisabled is only called once at the start.

Would love both an answer and some tips on how to debug this.

<template>
  <f7-page name="home">
    <f7-list inset>
      <f7-list-item title="I've got my headphones on">
          <f7-checkbox slot="media" :checked="checked.headphones"></f7-checkbox>
      </f7-list-item>
      <f7-list-item title="I have 10 minutes to myself">
          <f7-checkbox slot="media" :checked="checked.time"></f7-checkbox>
      </f7-list-item>
      <f7-list-item title="I'm in a quiet space">
          <f7-checkbox slot="media" :checked="checked.quiet"></f7-checkbox>
      </f7-list-item>
    </f7-list>
    <f7-list inset>
        <f7-button :disabled="buttonDisabled" fill round>Let's get started</f7-button>
    </f7-list>
  </f7-page>
</template>

<script>
  export default {
    data: function() {
      return {
        checked: {
          headphones: false,
          time: false,
          quiet: false,
        }
      }
    },
    computed: {
      buttonDisabled() {
        return ! ( this.checked.headphones && this.checked.time && this.checked.quiet );
      }
    }
  }
</script>

You need to use @change in order to update the model for each of the checkboxes.

https://framework7.io/vue/checkbox.html

<f7-checkbox slot="media" :checked="checked.headphones" @change="checked.headphones = $event.target.checked"></f7-checkbox>