Hi,did you have a look to this KB:
https://community.fortinet.com/t5/FortiGate/Technical-Tip-IKEv2-Dialup-IPsec-tunnel-with-RADIUS-and/ta-p/220818
?Your RADIUS server supports MS-CHAPv2?
Some weeks ago, we have opened a ticket to Fortinet support and we had
got the same answer: change the FSSO polling agent port.The issue seems
be related to a driver that they're using in the F series. There should
be a fix in the next releases but f...