Possible bug: c.spec/fn-specs doesn't always work on aliased symbols

broken.clj

;; using clojure 1.9.0-alpha5
(ns aaa (:require [clojure.spec :as sp]))
(in-ns 'aaa)

(defn plus [a b] (+ a b))

(sp/fdef plus :args (sp/cat :a number? :b number?))

(assert (not (nil? (:args (sp/fn-specs 'plus)))))

(ns bbb (:require [aaa :as aa] [clojure.spec :as sp]))

(in-ns 'bbb)

(assert (not (nil? (:args (sp/fn-specs 'aa/plus)))))

(defn spec-plus [] (sp/fn-specs 'aa/plus))
;; uncomment the following line to fix it
;; (defn spec-plus [] (sp/fn-specs 'aaa/plus))

(ns ccc (:require [bbb :refer [spec-plus]]))
(in-ns 'ccc)

(assert (not (nil? (:args (spec-plus))))) ;; => FAIL