Forticlient VPN connection from mobile phone keep disconnecting frequently
Some of our staffs need to use the Forticlient VPN from their Android mobile phone to connect to FortiGate via VPN connection. But the VPN connection keep disconnecting after some period, such as 20+mins, 40+mins. I have changed the settings on the FortiGate side but it doesn't help. The settings on the phone is also tried, such as no battery optimization, always use network data etc., all useless.
I suspect it is caused by the Android OS, either network is cut off or the Forticlient mobile app is put into sleep mode when the phone is not in use, but I cannot confirm this.
Any one has the experience of FortiClient VPN on mobile phone, please help, thanks.