Forticlient SSL VPN on Android gets disconnected

Hi,

Users running Forticlient on Android, get disconnected from the SSL VPN.

The disconnects occur random, sometimes after a couple of minutes, sometimes it stays connected for over 30 minutes.

This only occurs on Android, not on iOS devices.

FortiOS 6.2.4

Forticlient app 6.4.3.0462

There have been multiple reports on the same issue on the Google play store for the FortiClient VPN app: https://play.google.com/store/apps/details?id=com.fortinet.forticlient_vpn&showAllReviews=true

Debug log from the FortiGate when such a user gets disconnected:

[174:root:65b7]tunnelStateCleanup:779 0x7f1e6f613f00::0x7f1e6f627000 [174:root:0]ipcp: down ppp:0x7f1e6f5a7000 caller:0x7f1e6f613f00 tun:57 [174:root:65b7]sslvpn_ppp_deassociate_fd_to_ipaddr:317 deassociate 10.212.135.8 to tun (ssl.root:57) [174:root:65b7]session removed s: 0x7f1e6f613f00 (root) [174:root:65b7]deconstruct_session_id:426 decode session id ok, user=[user.name],group=[Duo SSL VPN - Engineering],authserver=[int-duoproxy-ldap],portal=[ssl_vpn_office],host=[78.22.117.209],realm=[],idx=7,auth=16,sid=2495f036,login=1605269482,access=1605269482,saml_logout_url=no [174:root:0]sslvpn_internal_remove_one_web_session:2862 web session (root:user.name:Duo SSL VPN - Engineering:78.22.117.209:7 1) removed for User requested termination of service [174:root:65b7]sslvpn_release_dynip:1177 free app session, idx[7] [174:root:65b7]sslConnGotoNextState:305 error (last state: 1, closeOp: 0) [174:root:65b7]Destroy sconn 0x7f1e6f613f00, connSize=12. (root) [174:root:65b9]cliRead,551, read=0, tunnel finish. [174:root:65b9]tunnelStateCleanup:779 0x7f1e6f617b00::0x7f1e6f60e000 [174:root:0]ipcp: down ppp:0x7f1e6f638000 caller:0x7f1e6f617b00 tun:68 [174:root:65b9]sslvpn_ppp_deassociate_fd_to_ipaddr:317 deassociate 10.212.135.9 to tun (ssl.root:68) [174:root:65b9]session removed s: 0x7f1e6f617b00 (root) [174:root:65b9]deconstruct_session_id:426 decode session id ok, user=[user2.name],group=[Duo SSL VPN - Engineering],authserver=[int-duoproxy-ldap],portal=[ssl_vpn_office],host=[178.117.216.80],realm=[],idx=12,auth=16,sid=43a81cf5,login=1605269566,access=1605269566,saml_logout_url=no [174:root:0]sslvpn_internal_remove_one_web_session:2862 web session (root:user2.name:Duo SSL VPN - Engineering:178.117.216.80:12 1) removed for User requested termination of service [174:root:65b9]sslvpn_release_dynip:1177 free app session, idx[13] [174:root:65b9]sslConnGotoNextState:305 error (last state: 1, closeOp: 0) [174:root:65b9]Destroy sconn 0x7f1e6f617b00, connSize=11. (root)