After many rewrites and much debugging, video syncing finally works properly.

Assets/UdonSharp/Game Managers/CaseManager.cs

@@ -116,8 +116,6 @@ public class CaseManager : UdonSharpBehaviour
 		_CaseFileVideosFallback = CaseFile.FallbackVideoFiles;
 		_CaseFileClueImages = CaseFile.ClueImages;
 
-		_Round1Manager.SetNewVideoPlayerLists(_CaseFileMaps, _CaseFileVideos);
-
 		VRCStringDownloader.LoadUrl(_CaseFileCluesURL, (IUdonEventReceiver)this);
 	}
 
@@ -268,6 +266,10 @@ public class CaseManager : UdonSharpBehaviour
 		return CrookToString(_AccusedCrook);
 	}
 
+	public VRCUrl[] GetMaps()
+	{
+		return _CaseFileMaps;
+	}
 	public VRCUrl GetMap(int MapIndex)
 	{
 		return _CaseFileMaps[MapIndex];
@@ -282,6 +284,10 @@ public class CaseManager : UdonSharpBehaviour
 		return _CaseFileLootImage;
 	}
 
+	public VRCUrl[] GetVideos()
+	{
+		return _CaseFileVideos;
+	}
 	public int GetIntroVideo()
 	{
 		return _CaseIntroVideo;

Assets/UdonSharp/Game Managers/GameManagerRound1.cs

@@ -140,25 +140,9 @@ public class GameManagerRound1 : GameManagerBase
 		Interface.CommentUI.text = _CaseManager.GetCaseDescription();
 
 		_GameHasBegun = false;
-	}
 
-
-	public void SetNewVideoPlayerLists(VRCUrl[] Maps, VRCUrl[] Videos)
-	{
-		_VideoPlayer.SetNewLists(Maps, Videos);
-	}
-	public void TryIntroVideoLoad()
-	{
-		int IntroVideoIndex = _CaseManager.GetIntroVideo();
-		if (IntroVideoIndex >= 0)
-		{
-			_VideoPlayer.SetVideoIndexLocal(IntroVideoIndex);
-		}
-		else
-		{
-			Debug.LogWarning("[GameManagerRound1] Intro video index is currently invalid. Retrying...");
-			SendCustomEventDelayedSeconds(nameof(TryIntroVideoLoad), 1.0f);
-		}
+		_VideoPlayer.InitialiseLists(_CaseManager.GetMaps(), _CaseManager.GetVideos());
+		_VideoPlayer.SetVideoIndex(_CaseManager.GetIntroVideo());
 	}
 
 
@@ -1802,7 +1786,7 @@ public class GameManagerRound1 : GameManagerBase
 			if (Presentation.ContainsKey("Videos"))
 			{
 				DataList Videos = Presentation["Videos"].DataList;
-				_VideoPlayer.VideoIndex = (int)Videos[_QuestionSubstage].Number;
+				_VideoPlayer.SetVideoIndex((int)Videos[_QuestionSubstage].Number);
 
 				VideosAvailable = true;
 			}