Ethernet randomly slows down

[Semon]

Roughly once a month, any device connected to my router through an ethernet connection drops from its normal ~300Mbps down ~100Mbps up to ~8Mbps down ~5Mbps up while maintaining a high connection bandwidth to any device on wifi (~150 down on 5GHz. Which is the same even when ethernet is working correctly). The only way I've found to fix this issue is to reboot the router, which is fine, but id rather not have too as I do host a few things and I'm not always home to be able to reset it when the ethernet drops off a cliff. I find it really strange that ethernet is the connection type that draws the short straw here.

 

So, I guess my question is, is this an issue with the router its self, like a hardware fault or a memory leak? And should I get a different one?

 

Router info for those interested:

Model: AC750 Wireless Dual Band Gigabit Router: Archer C2 v1 00000002

Firmware version: 0.9.1 5.0 v0032.0 Build 170207 Rel.49213n

Country of origin (since I think this matters?): New Zealand

[OhioYJ]

My first guess would be the router. For a very long time I've been modifing my routers and cable modems and adding fans. I've found the additional cooling added stability and kept my speeds constant, especially during extended downloads. 

 

The other thing I've used before at my in-laws on a modem they didn't own, was a vacation timer. They needed to reboot it occasionally for it to work, so I just plugged it into a timer so it would cycle the power to it in the middle of the night when no one was using it. This was enough to keep it "stable" throughout the day when they were using it. 

 

Couple of thoughts / ideas.