Sadly i’ve already tryed using a different credential set, same issue. It’s not user related for sure, since the same user on a different client connects perfectly.
“Sadly” it works perfectly fine on a different endpoint. No log shown either, it’s like it never really tryes to connect
After the uninstall did you purge the directories from appdata & program data, then reboot before reinstalling?
Also on the wtf chance I fixed a fortigate issue one time with sfc /scannow Only time it has ever worked for me.
When you say disable IPv6 do you mean just on the network adapter? I had to disable IPv6 on both the physical adapter and the virtual adapters Forticlient creates for you in order to get a consistent fix.