When a client joins a server with Mirror & Unity, and then disconnects from this server, if it tries to re-join straight after I get this error below. Even if I reboot the server it still gives me the error so it's definitely something on the client that doesnt reset properly when disconnecting. Do you guys have any idea what it could be ?

Disconnecting connId=0 to prevent exploits from an Exception in MessageHandler: ArgumentException An item with the same key has already been added. Key: 168553816898140304 at System.Collections.Generic.Dictionary2[TKey,TValue].TryInsert (TKey key, TValue value, System.Collections.Generic.InsertionBehavior behavior) [0x000dd] in <376a33e968974713b24063a1aeb8934c>:0 at System.Collections.Generic.Dictionary2[TKey,TValue].Add (TKey key, TValue value) [0x00000] in <376a33e968974713b24063a1aeb8934c>:0 at Mirror.NetworkClient.PrepareToSpawnSceneObjects () [0x00020] in /Users/martinb/Documents/Unity Repositories/COPE Multi/Assets/Mirror/Runtime/NetworkClient.cs:1129 at Mirror.NetworkClient.OnObjectSpawnStarted (Mirror.ObjectSpawnStartedMessage _) [0x00000] in /Users/martinb/Documents/Unity Repositories/COPE Multi/Assets/Mirror/Runtime/NetworkClient.cs:1137 at (wrapper delegate-invoke) System.Action1[Mirror.ObjectSpawnStartedMessage].invoke_void_T(Mirror.ObjectSpawnStartedMessage) at Mirror.NetworkClient+<>c__DisplayClass51_01[T].g__HandlerWrapped|0 (Mirror.NetworkConnection _, T value) [0x00000] in /Users/martinb/Documents/Unity Repositories/COPE Multi/Assets/Mirror/Runtime/NetworkClient.cs:441 at Mirror.MessagePacking+<>c__DisplayClass6_02[T,C].<WrapHandler>b__0 (Mirror.NetworkConnection conn, Mirror.NetworkReader reader, System.Int32 channelId) [0x0007a] in /Users/martinb/Documents/Unity Repositories/COPE Multi/Assets/Mirror/Runtime/MessagePacking.cs:118 UnityEngine.Debug:LogError (object) Mirror.MessagePacking/<>c__DisplayClass6_02<Mirror.ObjectSpawnStartedMessage, Mirror.NetworkConnection>:b__0 (Mirror.NetworkConnection,Mirror.NetworkReader,int) (at Assets/Mirror/Runtime/MessagePacking.cs:122) Mirror.NetworkClient:UnpackAndInvoke (Mirror.NetworkReader,int) (at Assets/Mirror/Runtime/NetworkClient.cs:292) Mirror.NetworkClient:OnTransportData (System.ArraySegment1<byte>,int) (at Assets/Mirror/Runtime/NetworkClient.cs:351) Mirror.SimpleWeb.SimpleWebTransport:<ClientConnect>b__32_1 (System.ArraySegment1) (at Assets/Mirror/Runtime/Transport/SimpleWebTransport/SimpleWebTransport.cs:153) Mirror.SimpleWeb.SimpleWebClient:ProcessMessageQueue (UnityEngine.MonoBehaviour) (at Assets/Mirror/Runtime/Transport/SimpleWebTransport/Client/SimpleWebClient.cs:69) Mirror.SimpleWeb.SimpleWebTransport:ClientEarlyUpdate () (at Assets/Mirror/Runtime/Transport/SimpleWebTransport/SimpleWebTransport.cs:195) Mirror.NetworkClient:NetworkEarlyUpdate () (at Assets/Mirror/Runtime/NetworkClient.cs:1322) Mirror.NetworkLoop:NetworkEarlyUpdate () (at Assets/Mirror/Runtime/NetworkLoop.cs:182)