I have a flat single LAN network with no other DHCP servers, and even have the LAN VLAN configured with "Legal DHCP Servers" set to the IP of the ER707 IP (192.168.4.1). Starting with in the last week or two, multiple clients (but only a few out of ~100) have started to be given an IP address other than what they are configured for, which is causing problems since they have some IP-specific policies that then break. When this happens, I cannot ping, or see anything else active, on the IP address they are supposed to receive via DHCP from the router, so it is not that the IP is in use. Also, as soon as I reboot the ER707 the problem fixes itself for a while at least and the devices resume being assigned their correct configured Fixed IP. In the even log I see logs like this - note that 4.81 is configured as the Fixed IP for this MAC (and I have even now set it as an IP-MAC binding to see if that would help, it did not):

Gateway DHCP Server Module Information    DHCP Server rejected the request of the client[MAC: 00-9d-6b-f6-87-97 IP: 192.168.4.180]. Mar 30, 2025 09:51:13 pm    

Gateway DHCP Server Module Information    DHCP Server allocated IP address 192.168.4.180 for the client[MAC: 00-9d-6b-f6-87-97]. Mar 30, 2025 09:51:13 pm    

Gateway DHCP Server Module Information    DHCP Server rejected the request of the client[MAC: 00-9d-6b-f6-87-97 IP: 192.168.4.180]. Mar 30, 2025 09:48:52 pm    

Gateway DHCP Server Module Information    DHCP Server allocated IP address 192.168.4.180 for the client[MAC: 00-9d-6b-f6-87-97]. Mar 30, 2025 09:48:52 pm    

Gateway DHCP Server Module Information    DHCP Server allocated IP address 192.168.4.180 for the client[MAC: 00-9d-6b-f6-87-97]. Mar 30, 2025 09:47:41 pm    

Gateway DHCP Server Module Information    DHCP Server rejected the request of the client[MAC: 00-9d-6b-f6-87-97 IP: 192.168.4.81]. Mar 30, 2025 09:47:40 pm

I will attach screenshots of the relevant configuration. This only recently started happening, but I am not sure exactly when it first began. I did somewhat recently update the controller to 5.15.20.16, and also updated two of my Omada switches to fix a different bug:

SG2008P v3.20    3.20.5 Build 20250117 SG2008Pv3_en_3.20.9_[20250304-rel77614]_up.bin Mar 23, 2025 11:14:22 pm
SG2210MP v4.20    4.20.6 Build 20250117 SG2210MPv4_en_4.20.10_[20250304-rel77614]_up.bin Mar 23, 2025 11:06:35 pm