How do I make assertions consistently wait until a turbo frame has been updated?

My system tests are experiencing a race condition leading to inconsistent test results. Sometimes the turbo frame is updated before my assertion (test passes) and sometimes afterward (test fails).

View:

<div data-controller="filter">
  <%= form_with url: root_path, method: :get, data: { turbo_frame: "intakes", filter_target: "form", action: "change->filter#submit" } do %>
      <%= select_tag "country", options_for_select(@countries) %>
  <% end %>

  <%= turbo_frame_tag "intakes" do %>
      <table>
        <% @family_intakes.each do |family_intake| %>
          <tr>
            <td><%= family_intake.full_name %></td>
          </tr>
        <% end %>
      </table>
  <% end %>
</div>

This Stimulus controller submits my form on change event (ultimately updating the turbo frame):

export default class extends Controller {
  static targets = ["form"];

  submit(event) {
    this.formTarget.requestSubmit();
  }
}

Test:

class FamilyIntakesTest < ApplicationSystemTestCase
  test "Only intakes from selected country are displayed" do
    login
    select "Afghanistan", from: "country"
    assert_selector "td", text: family_intakes(:manizha).first
    assert_selector "td", text: family_intakes(:sayed).first开发者_开发知识库
    refute_selector "td", text: family_intakes(:mohammad).first
  end
end

Error:

Failure:
FamilyIntakesTest#test_Only_intakes_from_selected_country_are_displayed [/home/eric/<redacted>/test/system/family_intakes_test.rb:31]:
expected not to find visible css "td" with text "Mohammad", found 1 match: "Mohammad Ahmad". Also found "Manizha Ahmadi", "Sayed Shinwari", which matched the selector but not all filters.