Fail to login FortiClient VPN on iOS 15 device

Hi @roy123456,

PuTTY SSH1:
------------

get vpn ssl monitor
diagnose vpn ssl list
diagnose firewall auth list
dia vpn ssl statistics
exec vpn sslvpn list
get system status
diag vpn ssl stat

PuTTY SSH2:
------------

diag sys flash list
diag debug reset
diagnose debug console timestamp en
diagnose vpn ssl debug-filter src-addr4 x.x.x.x - Here x.x.x.x is the public IP of the user connecting.
diag debug appl sslvpn -1
diag debug appl fn -1
diag debug enable

wait till the VPN disconnect, disable the logs by executing

diag debug disable
diag debug reset

Hi sjoshi,

Please note that there are no popup page for enter username and password when I try to connect the VPN in FortiClient.
When click the “VPN” button, a popup page will show as attached. Then I click the “OK” or “cancel”, it will return to the startup page. 

Since the I cannot enter the username and password, I believe the VPN connection is not being established between the end device and the firewall at that moment, so the firewall log capture may not provide any useful information.

I found that someone has a similar symptom when connecting to the VPN with an iOS 15 device, but there is no solution for this issue.

https://community.fortinet.com/t5/Support-Forum/Forticlient-7-4-0142-will-not-display-login-screen-on-iPad-iOS/m-p/340353

Do you have any suggestions to resolve this issue?

Thank you.