@glf 

For those wired devices, try assigning a static IP address for them. Log in to the router and go to Advanced > Network > DHCP Server. Reserve and IP outside of the default DHCP range of the router such as: 192.168.0.50 - 192.168.0.70

If the issue is not a potential IP conflict, you can try moving them to different LAN ports.

@Tony I tried doing that the other day and keep getting an error "Enter an IP address within the IP address pool." my dhcp pool is 0.100 to 0.149, my desktop is currently at 0.131, and I've tried reserving several diff IPs outside of that 100-149 range and get the error for all of them. I can't figure out what I'm doing wrong. let me know if you have any suggestions for that.

@glf 

Try this workaround for now.

Set your pool to be .2 - 249, then make the reservations, then set your pool back to the original. The reservations you make should hold.

@Tony I had already went ahead and reserved the IPs that my devices received from dhcp and didn't have any issues for several days until the network dropped my desktop again with the reserved IP. I was able to disable and enable the network adapter and get back online this time and stay online the last few days so far, whereas previously I had to reboot the modem and router to get a new IP dhcp assigned. The TV didn't seem to lose its connectivity this time. So, now wondering if there's some network adapter settings that I need to adjust for how it talks to the router? thoughts? I've got the realtek pcie gbe family controller on windows 10 running the latest updated driver.

I'm fine sticking with the method of reserving and IP within the dhcp range, although it does seem that there are alot of users on this forum with the same issue of wanting to reserve and IP outside of the range. is tplink going to ever change that?

@Tony my ethernet connects (desktop & tv) dropped overnight. they haven't reconnected after trying to disable/enable the adapter, which had worked before. Reboot of the router and the modem didn't work. All wifi devices stayed connected overnight and reconnected after reboot. I'm out of ideas and will have to return this thing soon.

@Tony ???

@Tony not sure why I never get any replies to my problem? Desktop and TV were disconnected again last night, can't reconnect without a modem and router reboot. Both ethernet ports are highlighted in the network dashboard as if connected full duplex. Both show permanent lease time with reserved IP addresses in the client list. I've unplugged and replugged both wires on both ends. disable/enable network card. no luck on anything

@glf 

With respect to your computer, I'd first look up the network adapter manufacturer to look for the latest drivers, just to make sure old drivers may not be causing that.

As far as the TV, if reserving the IP on the router is not working, try setting a static IP on the TV itself rather than relying on the TV.

@Tony one of the first things I did at the start of this ordeal was update the network card driver. It's the same card in same desktop that I've had for a few years, and it never had this issue with my previous router. Same with the TV for the couple of years I've had it.

I'll try setting static IP on both the desktop and the TV themselves to see if that works. They had both been DHCP the entire time on old router.

any other suggestions? that's not much to go on.

@Tony I've had a new router, same model, (TP-Link WiFi 6 Router AX1800 Smart WiFi Router (Archer AX21) about two weeks now and still having the same issue. ethernet disconnects on tv and desktop every two/three days. the only fix I've found so far is to reboot the modem and the router. both ethernet devices have fixed IPs assigned within their own settings, no dhcp. any more suggestions? anyone else with the tplink team have suggestions?