VPN keep dropping.

Hi everyone,

I'm using Fortigate 90D are running 6.0.3.

I have 2 ISP and its run with balancing....

After upgrade to lastest firmware (before is 4.9), i got problem with VPN connection. It's keep dropping every 30s, connect and disconnect.

Something i dont know is if i disable 1 ISP and only keep 1 running so VPN will be ok, no disconnect but when 2 ISP are active, it will dropping after connect 30s.

Could your guys know what problem is it?

Thank you.