RBR20/RBS20 - Ethernet disconnects every 30 minutes

Hi there,

I have 2 desktops hooked up to an Orbi RBS20 satellite---router via ethernet cables, and recently (~3 weeks ago) both computers have been disconnecting/reconnecting to the internet every ~30 minutes. Devices connected over wifi (such as my laptop and phone) are completely fine - I ran ping tests to confirm this. I also want to clarify that this setup worked fine for months and I'm only recently seeing this issue.

Things I've tried so far:

- restarting router

- updating network adapter drivers

- disabling power management settings on drivers

- updating router firmware

- disabling iPv6 via this video ( https://www.youtube.com/watch?v=RmEoxH-Lx-Q )

- called Orbi support and changed MTU size from 1500 to 1472 (made it worse so I changed it back)

- factory reset router and satellite

- Called Shaw support and replaced modem with newer model

- followed protocols listed here ( https://support.microsoft.com/en-us/help/10741/windows-fix-network-connection-issues ) namely:

netsh winsock reset

netsh int ip reset

ipconfig /release

ipconfig /renew

ipconfig /flushdns

As well, when i run ipconfig /all after the disconnects, I notice that the DHCP lease expiry time gets bumped up ~30 minutes... not sure if that's relevant information. 

I don't think it's an issue with hardware or the ethernet cables/ports since the issue is replicated on 2 different PCs.. and I'm not sure what could've happened 3 weeks ago to cause this. Again, this was working for months and only recently started acting up.

Any help is appreciated, thanks.