BIG-IP randomly closing connection from .NET Application

We have BIG-IP F5 Load Balancer please see below version

ProductCode     : BIG-IP
ProductVersion  : 11.5.4
PackageVersion  : Build 1.0.286 - Fri Mar 18 14:22:54 PDT 2016
PackageEdition  : Hotfix HF1

Load Balancer got two Pool Memebers (Both Tomcat Web Application) We also have enabled OneConnect profile for persistence since we are have to support session Randomly we got from our Net Application:

 System.Net.WebException: The underlying connection was closed: A connection that was expected to be kept alive was closed by the server. ---> System.IO.IOException: Unable to read data from the transport connection: An existing connection was forcibly closed by the remote host. ---> System.Net.Sockets.SocketException: An existing connection was forcibly closed by the remote host

Do you know any thoughts around it ? Any bugs found in this version? The error is totally random any thought so it is hard for us to tell what is issue here?