phx-throttle doesn't appear to work

[bcardarella]

I have the following form:

        <.simple_form id="message-form" phx-change="validate" for={@form} phx-submit="send">
          <.input
            phx-throttle="1000"
            class={[
              "message-input",
              @form_disabled && "disabled"
            ]}
            type="TextField"
            field={@form[:message]}
            label="Message"
          />
          <:actions>
            <LiveButton
              class={[
                @form_disabled && "disabled"
              ]}
              type="submit"
            >
              <Image class="button-send" systemName="sailboat"/>
            </LiveButton>
          </:actions>
        </.simple_form>

the phx-throttle="1000" on the input should prevent the phx-change event from firing more than once per second.

The behavior is described here: https://hexdocs.pm/phoenix_live_view/bindings.html#rate-limiting-events-with-debounce-and-throttle

So fire immediately then ignore additional events until the timer in ms is expired.

It does appear that we have throttle behavior in the lib but maybe these aren't applying for form's in the way described above. This is supported on Web.