Right after installation, I noticed that two different devices (with different MAC addresses) are being assigned the same IP address in the LAN. Both devices received 192.168.104.11.

To test further, I changed the LAN network from 192.168.104.1/24 to 192.168.109.1/24. After this change, those same two devices were again assigned the same IP address (this time 192.168.109.2).

Neither of these devices has a static IP configured — which is also clear because after changing the LAN network, they correctly switched to the new subnet.

At the moment, I only have a few devices connected via Ethernet (like a server with iDRAC and a Wi-Fi router without DHCP enabled). So the network is very small.
 

This looks like a DHCP bug in the router. Has anyone else seen this behavior on the ER8411? Any ideas on how to fix or troubleshoot it?

Thanks in advance!