In my test environment, the August update (KB5005043) installed fine and had no issues after testing.
Last Thursday I installed the update on my domain controllers in production. It installed fine but then had some strange issues over the weekend.
Devices were not getting an address from either domain controller. They would show an APIPA address and ipconfig /renew would only get a timeout. After spending hours on the phone with Meraki and Fortinet looking at switch/firewall configs and packet captures, decided to uninstall the August update from one domain controller.
Firewall debug was showing the DHCP broadcast but the domain controller sent nothing back. After a reboot, clients started getting addresses again from that server. Uninstalled the update from the other domain controller and clients were pulling from that server also. In the test environment, Windows 10 clients had no issues getting a DHCP address.
Anyone else ever heard of such a thing? Searched around and found nothing but clearly it broke after installing the update.
It is a Fortigate 501E with 6.4.6 firmware. Multiple vLANs configured for DHCP relay to both domain controllers.