Announcements don't stay dismissed

[ArmandBernard]

This is my first submitted issue! Yay!

The issue

When I dismiss announcements on the main page of the site, they don't stay dismissed, returning on page refresh.

Investigation so far

Looking at the code in site-announcements.js, clicking the cross dismiss button sends a post request to the back-end, presumably saving to a database the announcements a user has seen to filter them out.

Front-end

Fetch to get announcements

The call is made to https://kitsu.io/api/edge/feeds/site_announcements/57044?include=subject. I believe 57044 here is my user id.
The data returns 4 announcements. Each announcement seems to be split between two objects. The first has an id and a link to the second object. The second object contains the content to be shown in the announcement. This is probably linked to the "data enrichment" mentioned by the site-announcements.js.

Fetch to dismiss

Once I click on the dismiss button, the correct announcemment id seems to be sent to the back-end.

The url has a matching id. https://kitsu.io/api/edge/feeds/site_announcements/57044/_read
The response is a 200 success code.

Back-end

Bear with me here, as I have never even seen ruby code before.

The controller routes seem to be defined in routes.rb. The relevant resource seems to be jsonapi_resources :site_announcements on line 142, with the appropriate route being

post '/feeds/:group/:id/_read', to: 'feeds#mark_read'

There seems to be a site_announcements controller, but that is basically empty.

Otherwise, the controller for feeds is feeds_controller.rb, which contains the mark_read action.

  def mark_read
    activities = feed.activities.mark(:read, params[:_json])
    render_jsonapi stringify_activities(activities)
  end

mark() here appears to be the function defined in activity_list.rb:

    def mark(type, values = true)
      values = [values] if values.is_a? String
      data["mark_#{type}"] = values
      self
    end

This seems to set the field "mark_read" to true depending on the passed in json, though I'm not sure.

this bit in activity_list.rb may also be relevant:

    %i[limit offset ranking mark_read mark_seen].each do |key|
      define_method(key) do |value|
        data[key] = value
        self
      end
    end

To be honest, though I can find related pieces of code on the back-end, I am struggling to find whats wrong given that I do not know the language. Hopefully the stuff I've done above will be helpful and someone can find whats wrong.