Ethernet Dropping Out Frequently , Dns Not Resolving...

Hello Again..
At my wits end here

Secondary, older W10 PC, up to date , not used for some time.

Went to logon and:
-cable ethernet drops out frequently: uninstalled, reinstalled Cards.
- then DNS not resolving message in Chrome, FF-page not loading, Edge wont even load.
-ethernet keeps dropping out.

Search, search, search....
- rebooted and updated Router and modem
-Uninstalled Webroot and ExpressVPN
- followed up with extensive debugging
: flush DNS, etc etc , release/renew, winsock reset, network reset
: redo DNS manually 8.8.8.8 and 8.8.4.4

Not fixed

Other PCs on same network: no issues
Phones on local wifi: no issues

Now looking for help...again...

 

Ooops: Also, same problem in safe boot with network..
Wifi also dropping out

Turned off IPV6

Messages from Network Diagnostics:
"DNS Server Not responding"

Should this be in HW subforum??

 

You may want to read this:

https://www.makeuseof.com/ethernet-keeps-disconnecting-windows/

and try steps 3, 4, and 6.

For the wifi dropping:

https://www.thewindowsclub.com/wifi-keeps-disconnecting-in-windows

It looks like power management might be a common element.