HTML formatting in notifications - tags visible when notification collapsed

Running 0.112.4 with v1.11.2-221 of the Android app and webview v84.0.4147.89 on a Pixel 3.

After the recent (much appreciated) updates to the Android app I added some very basic HTML formatting to some of our mobile notifications, e.g.:

    - service: notify.all_mobile
        title: "CatFlap Warning"
        message: >
           {% if trigger.entity_id == 'binary_sensor.pet_sami' %}
               It looks like <b>Sami</b> has been outside for more than 3 hours.<br> 
               She left the house at {{ as_timestamp(state_attr('binary_sensor.pet_sami', 'since')) | timestamp_custom('%d-%b-%Y %H:%M', true) }}.
           {% else %}
               It looks like <b>Fig</b> has been outside for more than 6 hours.<br> 
               He left the house at {{ as_timestamp(state_attr('binary_sensor.pet_fig', 'since')) | timestamp_custom('%d-%b-%Y %H:%M', true) }}.
           {% endif %}
          group: Cats

However I’ve noticed that the formatting is ignored when the notification is in a collapsed state and represented literally e.g. “It looks like Fig has been outside for than 6 hours.
” is shown in the collapsed view.
When the notification is expanded, the tags disappear and the formatting is asserted.
This occurs regardless of tags used.

Is this expected behaviour or can I mitigate it in some way?