R6350 ethernet doesn't work properly

I purchased a Netgear R6350 on January 7th, 2019 and it has never worked correctly. Since I mostly use my desktop plugged into ethernet I have mostly just been staying plugged into the modem and only using the router when I need to download something on my phone, but it's starting to inconvenience me. Here is what is happening.

The wifi seems to work without issue. The ethernet does not. The ethernet will work, but only after resetting my computer and resetting the router from within the router's login. Sometimes it takes several series of resets for this to work. The ethernet stops working everytime my computer goes to sleep, necessitating more resets. It will also occasionally stop working seemingly at random while I'm still using it, requiring more resets.

I am 100% certain that this is an issue with this router specifically. I have an older netgear router that I gave to a family member that works flawlessly, both wifi and ethernet, with the exact same cables and the exact same computer at both my house and my family member's house. Furthermore I have taken the R6350 over to that family member's house, which has a different modem and it becomes even less functional.  The wifi doesn't even work, plugging it into the modem seems to put the modem into some kind of weird power cycle. I can log into the router via ethernet, but in completely fails to find an internet connection.

I have factory reset the router numerous times to no avail. It is currently on the most recent firmware and I have tried the previous 3 versions of the firmware to no effect. I am absolutely convinced that this router is either defective or there is something stupid that isn't obvious that I have never had to do with any previous router.

Is there something that anybody can tell me that might help?

P.S. Why am I unable to select this router in the model section of this discussion template? According to this link, the R6350 supports the Nighthawk app.