I have the following components:

(fulcro-comp/defsc ForecastRow [_this _props]
  {:query [:forecast/id :forecast/name]
   :ident :forecast/id})

(fulcro-comp/defsc ForecastList [_this {:keys [forecasts-data] :as props}]
  {:query [{:forecasts-data (fulcro-comp/query ForecastRow)}
           [fulcro-fetch/marker-table 'ForecastList]]
   :initial-state {:forecasts-data []}}

(let [forecasts-data (fulcro-hooks/use-root fulcro/app :root/forecasts ForecastList {})]
    (fulcro-comp/with-parent-context fulcro/app
      (ui-forecast-list forecasts-data))

(fulcro-fetch/load! fulcro/app :forecasts ForecastRow
     {:target [:root/forecasts :forecasts-data]
      :marker 'ForecastList})

The first time the page loads, I am always receiving forecasts-data = nil, until the data is loaded. But then, if I do a reload, I do get the marker updates in forecasts-data.

Could this be related to what I experienced of Dynamic Routing not working on use-root, but working on use-component?

General hooks support is newer and not as well-tested than the traditional Fulcro composition techniques. I still recommend using the older mechanisms as the primary composition technique, and reserve the use of hooks for cases where dynamism is actually needed.

I use use-component way more than use-root

The dynamic routing system is designed to use the queries (from the real mounted app root, often) for various features. I guarantee use-root and dynamic routers will not be 100% compatible.

In terms of refresh of load marker: probably a bug. Im’ sure the load marker is going into state via load. Not sure why you’re getting a missed refresh on startup.

Thanks @U0CKQ19AQ. I'm not using detached roots as a way to structure the application, but as a means to progressively introduce Fulcro in an existing application.

Ah I see. Well I'm open to prs if you find an issue, or an issue with a simple reproducible problem. Eg make a repo with small example of problem that I can run and fix.