Do you mean reinstall? I.e., the OS and all of the appropriate drivers?
In any case the objective is to determine if the problem can be narrowed down to hardware or software.
My next suggestion would have been to uninstall the new mouse drivers and see if the generic mouse drivers work with the mouse. And then again test the ethernet port.
And I have seen a few postings regarding problems with the Killer LAN cards....
Plus Windows 10 has made some changes that has affected connectivity to various devices. A family member's One-Touch blood test meter stopped communicating with the computer. Reason turned out to be that Windows 10 no longer supported the proprietary USB to meter cable. The cable needs to be replaced accordingly. Vendor is sending the replacement cable....
Sort of out of ideas at this point. If Device Manager is still reporting the "Code 28" then a software problem related to Killer drivers is most likely. Or some resource conflict (perhaps via the new mouse drivers) that is somehow interferring.
Uninstall the new mouse. Try an external USB to ethernet adapter if you can purchase or borrow one.