Webpage Persistence Load balancing

I'm having a webpage Persistence problem, it is intermittent. I suspect it is caused by load-balancing. Specifically: Users are connected to a webpage form to complete. Generally, everything is OK if they take a minute or even more to complete the form. However, sometimes they report to me, and I've seen it myself, the connection has been dropped by the server in a short time. They enter the data and Submit it to the server, and the page just reloads and their data is lost. I have the PHP ignore_user_abort(true); etc. Is there anything I can do to fix this or is it a server issue that you must fix? Thanks, Al.........