FG enters conserve mode at 88% by default, at which point you can't make configuration changes. Also, without additional config, FG will drop sessions that require inspection. At 95%, all new sessions are dropped.

The sensor will allow attackers matching the Microsoft.Windows.iSCSITarget.DoS signature.
The action for this specific signature is set to Monitor, which means FortiGate will only detect and log the activity but will not block or reset the session.
The sensor will block all attacks aimed at Windows servers.
The general Windows filter is configured with the Block action, so any traffic matching Windows- related attack signatures will be blocked.

For traffic that does not match any of the defined SD-WAN rules, the default implicit SD-WAN rule is applied. By default, the FortiGate uses a "source-destination IP-based" algorithm, which means all traffic from a specific source IP to a specific destination IP is sent through the same interface.
This ensures that a consistent path is used for traffic between the same source and destination IP addresses.

Web filter profiles with category usage quotas require the firewall policy to be in proxy-based (deep) inspection mode; if the inspection mode does not match this requirement, the profile will not appear in the drop-down list.

In this scenario, the FortiGate uses a Virtual IP (VIP) to map the external IP 203.0.113.22 to the internal web server 10.0.1.10. When using VIPs, firewall policies must be configured carefully to match the translated destination address.
The external users (Remote-User1 and Remote-User2) connect to 203.0.113.22, which is the VIP for the web server.
By default, firewall policies match pre-NAT addresses (the original destination before VIP translation).
To make the deny policy recognize traffic destined for the VIP-mapped address, the match-vip option must be enabled.
The destination in the Deny policy should explicitly be the Webserver (the VIP object), so FortiGate correctly identifies the target.