fortinet vpn client not receiving packets

It happens frequently to a handful of users and almost never for everyone else, so I'm thinking the problem is less FortiClient and more Windows related. This all is made even more confusing by the fact that not every one of our users who's tried this seems to run into this problem. There doesn't seem to be any indicators in the FortiClient logs as to what's happening and nothing gets populated in the Windows event logs either. At no point during this 'disconnect' does FortiClient complain about being disconnected, it just sits there happily connected to the VPN gateway.

Inexplicably traffic just won't go for up to a couple minutes and then suddenly it recovers and it's fine. What will happen is traffic to internal resources stops getting routed down the VPN tunnel, sometimes even when my internet connection is otherwise strong and stable and I can still reach the VPN gateway. I can't reliably reproduce it but I can make it more likely to occur by using a 'worse' internet connection, in this case a personal hotspot from an iPhone. What I'm seeing is fairly frequent 'drops' in connection over the tunnel after it's been established. I'm hoping someone here has run into similar issues before and been able to find a fix for the problem We unfortunately do not (currently) have a support contract that includes in-depth technical support on the FortiClient side and I've been through the channels on the FortiGate side on everything that's available for them to tell me. I'm looking for some help with getting our Fortinet SSL VPN using FortiClient into a stable and workable state.

Fortinet vpn client not receiving packets