.Completed stays "running" even though connection has been dropped

[lostmsu]

I run RPC over WebSocket with WebSocketMessageHandler and SystemTextJsonFormatter.

I get a weird behavior where something breaks with the connection underlying RPC, but Completion task stays running for a while before finally I get an error.

I get the WebSocket from ASP.NET AcceptWebSocketAsync.

JsonRpc Critical: 13 :
Connection closing (StreamError: Reading JSON RPC from the stream failed with WebSocketException: The remote party closed the WebSocket connection without completing the close handshake.). System.Net.WebSockets.WebSocketException (0x80004005): The remote party closed the WebSocket connection without completing the close handshake.
    at System.Net.WebSockets.ManagedWebSocket.ThrowEOFUnexpected()
    at System.Net.WebSockets.ManagedWebSocket.EnsureBufferContainsAsync(Int32 minimumRequiredBytes, CancellationToken cancellationToken)
    at System.Runtime.CompilerServices.PoolingAsyncValueTaskMethodBuilder`1.StateMachineBox`1.System.Threading.Tasks.Sources.IValueTaskSource.GetResult(Int16 token)
    at System.Net.WebSockets.ManagedWebSocket.ReceiveAsyncPrivate[TResult](Memory`1 payloadBuffer, CancellationToken cancellationToken)
    at System.Runtime.CompilerServices.PoolingAsyncValueTaskMethodBuilder`1.StateMachineBox`1.System.Threading.Tasks.Sources.IValueTaskSource<TResult>.GetResult(Int16 token)
    at StreamJsonRpc.WebSocketMessageHandler.ReadCoreAsync(CancellationToken cancellationToken)
    at StreamJsonRpc.MessageHandlerBase.ReadAsync(CancellationToken cancellationToken)
    at StreamJsonRpc.JsonRpc.ReadAndHandleRequestsAsync()

I guess my question is how can I make it notice faster?