Fix beatmap leaderboard potentially showing incorrect leaderboard

osu.Game/Screens/Select/Leaderboards/BeatmapLeaderboard.cs

@@ -104,6 +104,9 @@ namespace osu.Game.Screens.Select.Leaderboards
 
         protected override APIRequest? FetchScores(CancellationToken cancellationToken)
         {
+            scoreRetrievalRequest?.Cancel();
+            scoreRetrievalRequest = null;
+
             var fetchBeatmapInfo = BeatmapInfo;
 
             if (fetchBeatmapInfo == null)
@@ -152,8 +155,6 @@ namespace osu.Game.Screens.Select.Leaderboards
             else if (filterMods)
                 requestMods = mods.Value;
 
-            scoreRetrievalRequest?.Cancel();
-
             var newRequest = new GetScoresRequest(fetchBeatmapInfo, fetchRuleset, Scope, requestMods);
             newRequest.Success += response => Schedule(() =>
             {