C2300 becomes unreliable when I add an access point
I have an Archer C2300 as my main router, and I recently added an older C5 as an access point on the network. (I connected the C2300 and C5 through their LAN ports, turned off DHCP on the C5, and assigned the C5 an IP address of 192.168.0.254). While the C5 operates properly in access point mode, the online interface of the C2300 behaves erratically when the C5 is connected. The C2300 client list becomes unreliable; sometimes it shows wired clients as wireless or vice versa. Other times, no clients appear at all, even though they're connected and functioning. Also, the C2300 Parental Control "Profile" list and the QOS "Device Priority" list appear blank. The Tether app also behaves oddly. It can see the C5, but it shows the C2300 as generic TP Link router that it says cannot be controlled with the app. This happens even if my phone is connected to the C2300.
All these issues clear up if I disconnect the C5 access point and reboot the C2300.
Is there any fix for this?
Thank you.