Electric datalevin pending weird behaviour

core.cljc

(ns app
  (:require [hyperfiddle.electric :as e]
            [hyperfiddle.electric-dom2 :as dom]
            [hyperfiddle.electric-ui4 :as ui]
            #?(:clj [datalevin.core :as d])
  (:import (hyperfiddle.electric Pending)))

#?(:clj
   (defonce !conn (d/get-conn "/tmp/foo")))

(comment
  (d/close !conn)
  (alter-var-root #'!conn (constantly (d/get-conn "/tmp/foo")))
  nil)

(e/def db)

#?(:clj
   (defn add-item []
     (d/transact! !conn [{:db/id -1 :item/id (random-uuid)}])))

#?(:clj
   (defn list-items [db]
     (d/q '[:find [(pull ?e [:item/id]) ...]
            :where [?e :item/id]]
          db)))

(e/defn App []
  (e/server
   (binding [db (e/watch !conn)]
     (e/client
      (ui/button
       (e/fn [] (e/server (e/offload #(add-item)) nil))
       (dom/text "+ Add an item"))
      (dom/ul
       (e/server
        (try
          (let [items (e/offload #(list-items db))]
            (e/for-by :item/id [{:keys [item/id]} items]
                      (e/client
                       (dom/li (dom/text id)))))
          (catch Pending _ (e/client (dom/p (dom/text "Loading...")))))))))))