Wifi works, Ethernet Doesn't

At this point, i've asked this question on 4 different sites without a single suggestion so i'm pretty stuck. I've spoken to tech specialists who also gave no useful solutions. The reasoning being that the issue makes no sense whatsoever.

A few weeks ago, my Ethernet spontaneously stopped working, at this point I disconnected my ethernet cord to find that the wifi was working normally.
I then tested 3 different PC's in the ethernet port to find all were having the same issue.

After this I plugged my Smart TV into the ethernet port and found that it's ethernet connection was working with no issues whatsoever.

I then proceeded to test 2 laptops in 4 different rooms around the house, all ethernet ports gave the same issue, yet all ethernet ports had internet access when tested with a smart tv.

The Ethernet ports in the rooms are wall ports so they aren't directly connected into the router, and when I connect any device directly into the router using an ethernet cord it works with no issues.

So at this point I've determined.
we don't actually have any internet issues lol.
2. the Ethernet ports work fine
3. the Ethernet cord/s work fine
4. All the pc's have no issues
5. The router is working normally
6. the signal is being correctly sent (as the smart tv's have internet access).

I'm just incredibly confused as to why all Desktop/laptop computers wont connect to the internet via the same ethernet port which is working entirely fine for smart tv's yet they will all connect to wifi, and all connect when connected directly into the router. The Ethernet port is simply a signal extension of the router, so if it was having issues, the tv wouldn't connect to the internet. What settings are there that could potentially effect desktops/laptops yet not tv's? They have no similarities which could be causing the issue (they're all running different operating systems).

I've tried the following fixes...(the issue has been going on for over a month so i've likely tried things which i've forgotten to mention here)

Static Ip's.
Ressetting the router entirely.
Tested a second router.
Flat restore on one of the computers.
Reinstalling/updating drivers
Disabled wifi.
I also tried a heap of registry changes.
Most of these changes were likely irrelevant as they involved changing pc settings yet the issue doesn't seem to be related to any of the pc's.