DNS problems over Ethernet, Wifi still works

Hi Everyone,

I have an MT7711 modem/gateway which I installed about a week ago. 

Things have been working fine except a few days after install I noticed that my computer (connected via ethernet) was experiencing very slow internet after I would wake it up from sleep mode and wouldn't go back to normal again until I unplugged/ plugged the ethernet cable back in (sometimes I need to do this several times). Windows troubleshooting and event viewer say it's a DNS problem. Resetting the ethernet adapter usually temporarily fixes it, but as soon as the computer goes into sleep mode, it happens again. All devices connected via Wi-Fi are working fine. I have a USB wifi adapter on my desktop and that seems to be working fine as well. 

I have tested the ethernet on a laptop which seemed to work, so I'm inclined to think it's just the desktop.

Things I have tried:

Set Modem DNS from the default Comcast DNS to Cloudflare and Google 1.1.1.1, and 8.8.8.8 AND set those as the default DNS servers on network settings.

Updated ethernet adapter driver via the windows option on device manager (though I think it just reinstalled the same driver from 2018)

FlushedDNS and renewed IP in command prompt 

went into device manager and unchecked the box to "allow windows to disable this device to save power"

used a different ethernet cable and ethernet ports on the modem

Scanned for viruses (Malwarebytes)

resetting the modem seems to temporarily fix it as well as rebooting the PC. 

thanks in advance!