Seems you don't have a DHCP Server. PCs, printers and APs can set static IP, but how about those mobile phones? Can you also set static IP on them? Or Unifi AP can work as a DHCP server? If all...

Do you have Omada gateway? What's the firmware of it?

By DHCP leases, do you mean DHCP Client list? Controller has the Client menu. Is this what you want?

Seems IP conflict issue or configuration issue. What are the IP addresses of your modems? Check if there is any IP conflict in your network environment. ER605's default LAN IP is 192.168.0.1. The IP...

@cegan09 The beta firmware is for the issue of SSID VLANs, not for your case. I saw quite a few people have the same issue in other threads, but TP-Link said it's not easy to optimize it. See this...

@TonyAB It doesn't matter what kind of router you have. VLAN and QoS settings for VoIP should be configured on the switch, not on the router. So what you need is a switch that supports VLAN and QoS....