React-native-render-html, cannot style text bold

Question

I Am trying to style the following content. I cannot get the class="content-bold" to style bold. Can anyone help?

<p>xxx</p>
<p class="content-bold">xxx <a href="tel: 0330 159 0740" target="_self">xxx</a></p>
<p class="bold">To opt out, please go to Account Settings on <a href="https://xxx" target="_self">xxxx</a></p>

My component:

const systemFonts = ['Frederick Simms Regular', 'Frederick Simms Bold'];
    <RenderHtml
      systemFonts={systemFonts}
      tagsStyles={{
        p: {
          fontFamily: 'Frederick Simms Regular',
        },
      }}
      classStyles={{
        'content-bold': {
          fontFamily: 'Frederick Simms Bold',
          fontWeight: 'bold',
        },
      }}
      source={{
        html:
          (renewalStatus
            ? data?.pageBodyOptedIn
            : data?.pageBodyOptedOut) || '',
      }}
      renderersProps={{ a: { onPress: clickHandler } }}
    />