Web clients losing authentication from OAM 10.1.4.3

Hello,Using OHS 11.1.1.5, Weblogic 10.3.5, OIM 11.1.15, and OAM 10.1.4.3. We have an application that LAN users have no problem accessing and moving around the application as intended. External users are experiencing a behavior where they'll be able to authenticate, then after a very short random amount of time (much, much shorter than the user session timeout set in OAM), they will get kicked out to the authentication form like they lost their obSSOCookie. I realize this could be a number of things, but has anyone gone through this before? Could it be a firewall issue? I guess it could