Advent of Code 2020, Day 22... can't find the bug

aoc-2020-day22.clj

(def game {:player1 [26 8 2 17 19 29 41 7 25 33 50 16 36 37 32 4 46 12 21 48 11 6 13 23 9],
           :player2 [27 47 15 45 10 14 3 44 31 39 42 5 49 24 22 20 30 1 35 38 18 43 28 40 34]})
;; Treating the seen rule as needing to see the exact game (both decks) twice.
;; Doesn't terminate.
(defn play-round [game]
  (loop [seen #{}
         {:keys [player1 player2] :as game} game]
    (if (or (empty? player1) (empty? player2))
      game
      (let [p1 (player1 0)
            p2 (player2 0)
            p1s (subvec player1 1)
            p2s (subvec player2 1)    
            winner (cond (seen game) :player1 

                         (and (<= p1 (count p1s)) (<= p2 (count p2s)))
                         (play-round {:player1 (subvec p1s 0 p1)
                                      :player2 (subvec p2s 0 p2)})

                         :else (if (> p1 p2) :player1 :player2))]

        (recur (conj seen game)
               (if (= winner :player1)
                 {:player1 (conj p1s p1 p2) :player2 p2s}
                 {:player1 p1s :player2 (conj p2s p2 p1)}))))))


;; Treating the seen rule as meaning you must only see one deck twice.
;; Terminates but with wrong answer
(defn play-round [game]
  (loop [seen #{}
         {:keys [player1 player2] :as game} game]
    (if (or (empty? player1) (empty? player2))
      game
      (let [p1 (player1 0)
            p2 (player2 0)
            p1s (subvec player1 1)
            p2s (subvec player2 1)
            winner (cond (or (seen (:player1 game))
                             (seen (:player2 game))) :player1

                         (and (<= p1 (count p1s)) (<= p2 (count p2s)))
                         (play-round {:player1 (subvec p1s 0 p1)
                                      :player2 (subvec p2s 0 p2)})

                         :else (if (> p1 p2) :player1 :player2))]

        (recur (into seen (vals game))
               (if (= winner :player1)
                 {:player1 (conj p1s p1 p2) :player2 p2s}
                 {:player1 p1s :player2 (conj p2s p2 p1)}))))))

(defn score-game [game]
  (->> game
       (play-round)
       vals
       (keep seq)
       first
       reverse
       (map-indexed (fn [i x] (* (inc i) x)))
       (reduce +)))