version:3.1.0,AsyncHttpServer not work

1,when client send get request and set "Content-Type", "application/json;charset=utf-8" ,the service is not responding? AsyncHttpServer onAccepted return exception cause:Socket.close(),but version 2.1.0 is ok.

2,When the client requests multiple times at the same time, there will be a delay of 10s ~ 15s？