Setting up automatic IP blocking can definitely help ease the burden.
One option is using tools like fail2ban or ModSecurity with custom rules
to detect and block suspicious activity.
If updating doesn't do the trick, you could try this: disconnect from
the VPN, forget the WiFi network, reconnect to the WiFi, and then give
the VPN another shot.
I think it is not a fortinet problem but if speaking about problems with
VPN I can say that you are not the only one and it might be a useful
subject. I also had problems with NordVPN because it was slow and some
websites thought it was spam. So, I s...
Check if those ports are already assigned to something else, like maybe
they're part of another VLAN or something. Also, verify if the switches
are recognizing the ports correctly.