fastl4 Protocol Profile turning on

Hi Guys update to the issue. Unfortunately the customer faslL4 protocol profile has not worked as expected. infact it has made no difference at all to the issue. The client does a bulk file tranfer using LFTP and it seems to freeeze once it reached 24 files. The client cannot reconnect until after about an hour or so. When the client adds a 2 sec delay between files all the files are copied across without any issues. The issue seems to occur when they copy ALL files in one hit? Im running out of ideas here and not sure what else the F5 can do to assist the situation and im un a battle with the application team who blame the network. and the network team (myself) blame the app or the server either way we have had a week of this with very little progress albeit the workaround in place